72 Demon slanty-to-340 Resto

[moparmat2000]

If the eddys are a bit pricey, check out the bare pro comps at $414 each. Machined for chevy 2.02-1.60 valves. They are eddy copies. I got mine for $250 each when they first came out. Nobody wanted to touch em back then 3 years ago. Now people are realizing they are decent parts.

 

[knote72]

If the eddys are a bit pricey, check out the bare pro comps at $414 each. Machined for chevy 2.02-1.60 valves. They are eddy copies. I got mine for $250 each when they first came out. Nobody wanted to touch em back then 3 years ago. Now people are realizing they are decent parts.

Yeah there are a number of single plane intakes I can pick from, not as many as dual planes but I still have options. That one just happens to be attached to a whole sequential EFI kit, the best stage of EFI short of the latest direct injection. Better efficiency and atomization than the throttle body efi kits that are almost everywhere. It just kills me how pricey that kit is.

 

[moparmat2000]

Pro comp speedmaster heads i was talking about. They look like LAs but have chambers, ports, and runners like magnums. Guides are junk, but thats easily remedied. I wouldent buy the built up ones either, just the bare heads, and use good valves, guides, and springs

 

[knote72]

Pro comp speedmaster heads i was talking about. They look like LAs but have chambers, ports, and runners like magnums. Guides are junk, but thats easily remedied. I wouldent buy the built up ones either, just the bare heads, and use good valves, guides, and springs

Oh gotcha, got any recommendation where I can get valves, springs, etc? Comp Cams and Jegs don't turn up much in those parts.

 

[moparmat2000]

No, not much. My machinest will be building mine up in the near figure . I believe they are machined for Chivvy parts, so retainers, springs, keepers etc would be that. If thats the case, it would make it cheaper to build em up.

 

[72bluNblu]

Since I forgot to carry it over from the last thread, I'm gonna make a quick list of parts I'm after so far. Something to keep me focused on til a bodywork project gets underway. Feel free to comment (within reason, the fallback on asking opinions is apparently no two can quite agree on something)

• 340 block + k-member - no known crate engines made, so I gotta find out where to look for one that might be lurking in my state (some people thought I should just get a 408 stroker block, forgetting I wanted to keep to small block size/weight). If finding a k-member proves unsuccessful, QA1 makes a tubular one I can fall back on QA1 52313: Tubular K-Member 1967-72 Mopar A-Body | JEGS
  
• T56 or Passon A855 trans
• Since I didn't grow up with the familiarity of tuning carbs, and don't hold any stigma towards EFI, that's the way I'm going Edelbrock 32530: Pro-Flo 3 EFI System Small Block Chrysler | JEGS This set looks nifty, but isn't the only one I'm considering. Even with the cost of distributor, intake, throttle body, ECU and efi necessities considered, it's still spendy. In the last thread a few noted the intake is single plane and said that I shouldn't use a single plane, but they forgot the little fact that EFI doesn't play nice with dual planes. The one luxury a carb has over EFI.
• Gotta have a nice light set of cylinder heads Edelbrock 60775: Performer RPM Cylinder Head for Small Block Chrysler | JEGS
  
• Cam choice? Thoughts on how this will work with the intake? 20-811-9 - Xtreme Energy™ Retro-Fit Hydraulic Roller Camshafts I had some difficulty in the last thread getting thoughts on this one, responses kept trailing off to "why don't you just get a stroker setup" instead of addressing my question. I know that heads, intake and cam pairings greatly affect flow but I'm still green on proper pairings (I at least know the cam won't exceed max valve lift). If I could get thoughts on this intake/head/cam pairing instead of "why don't you just get a stroker", I'd appreciate it.
• I had a header choice in the last thread but someone said they wouldn't fit. Anybody have a set to recommend?
• Stock radiator is GACKED, gonna need a new one Champion Cooling Systems CC526: All-Aluminum Radiator 1970-1972 Plymouth Duster & Dodge Dart | JEGS and while I'm at it I figure I'd go with electric fans to get with the times and free up some hp while I'm at it Flex-a-lite 180: Black Magic X-Treme Electric Puller Fan Includes adjustable thermostat controller | JEGS They had an "easy set" with radiator and electric fan and all hardware, but that fan pulled fewer cfms and pulled more amp draw. I just copied down the extra hardware bits separately.
• It has a 7.25" rear, no good, so gonna search every yard in the state if I have to for a proper width 8.25" or 8.75". I'll get a limited slip and 3.55 gears for it to swap in.
• With the electric fan and efi system drawing additional power, will an upgrade alternator be a must?
• It was greatly recommended I get subframe connectors
• Torsion bars look like they could do with replacement too. What size should I be going with?
• The EFI system will demand a high pressure fuel system, but there are a couple routes I can go with that
• I haven't given much thought to clutch, have I? Centerforce KDF693963: DF COMPLETE CLUTCH KIT | JEGS just throwing an option out there. Also may go hydro clutch if not already there.

Quite the shopping list. Good thing I got time to space it out. I'll definitely look to save money where I can, but if it must cost more to get it done right the first time then so be it. A well-built, small block car with some pounds dropped in the front end and won't mind a few corners (that's why I don't wanna "just get a stroker" and tack on all that extra iron on the front).

Most of this makes a lot of sense to me, except the whole bit about the stroker. I think you might misunderstand something here. A 408 stroker is just a small block 360 with a 4" crank. Going to a 408 stroker won't add any weight at all, usually the stroker rotating kits end up being lighter than stock small block rotating assemblies. The pistons and rods are lighter for sure. So, the overall weight of the engine shouldn't be any different than a 340 or 360 small block. As for the 340, having built one and paid for one I wouldn't bother again, the 360's are much easier to find and a lot cheaper usually. Since nothing you do will be matching numbers I wouldn't spend the extra cash for a 340 block.

For the radiator, I think I mentioned this before, I would go straight to a 26" 3 core and run the Ford contour set up. This thread has links to both my build and goldduster318's pdf on the Contour install Mopar Performance 360/380 running pretty hot. The thing is that black magic fan you have linked costs almost twice as much as the Contour fans, only has one speed, and only flows 3300 cfm. That would probably work, but the contour fans are OE proven parts that flow 3,500 and 5000 cfm (low and high speed) and cost less to boot.

For any electric fan set up capable of running stand alone I would say you should get a 100 amp alternator at the minimum. That's what I run, and it works well with my set up. I think the contour fans pull almost 40 amps at start up, so, even a stock 60 amp alternator would be pretty iffy.

Torsion bars I'd go with at least PST's 1.03's, if you're planning a more serious handling car Firm Feel's 1.06's or 1.12's (which is what I run) work well too. And you'll need Bilstein RCD's or Hotchkis shocks for any of those unless you hate your dental fillings and lumbar disks.

You absolutely should install subframe connectors at the minimum. Torque boxes would be very beneficial as well. And if you're looking at a handling car, some kind of foward supports (J bars or US Cartool inner fender supports) and a radiator support brace.

Doug's D453 headers will fit, so will TTI's, and I wouldn't bother spending the money on anything else. Those are both above the steering link, the other designs have tubes below the steering links and that isn't going to last on a lowered car. And they're not cheap enough to warrant buying a set to see if you smash them flat, most of them are more than half as much as the Doug's anyway, better to just do it right the first time.

I wouldn't worry about the clutch until you decide for sure on the transmission, because that will change.

Just my .02.

 

[knote72]

Most of this makes a lot of sense to me, except the whole bit about the stroker. I think you might misunderstand something here. A 408 stroker is just a small block 360 with a 4" crank. Going to a 408 stroker won't add any weight at all, usually the stroker rotating kits end up being lighter than stock small block rotating assemblies. The pistons and rods are lighter for sure. So, the overall weight of the engine shouldn't be any different than a 340 or 360 small block. As for the 340, having built one and paid for one I wouldn't bother again, the 360's are much easier to find and a lot cheaper usually. Since nothing you do will be matching numbers I wouldn't spend the extra cash for a 340 block.

For the radiator, I think I mentioned this before, I would go straight to a 26" 3 core and run the Ford contour set up. This thread has links to both my build and goldduster318's pdf on the Contour install Mopar Performance 360/380 running pretty hot. The thing is that black magic fan you have linked costs almost twice as much as the Contour fans, only has one speed, and only flows 3300 cfm. That would probably work, but the contour fans are OE proven parts that flow 3,500 and 5000 cfm (low and high speed) and cost less to boot.

For any electric fan set up capable of running stand alone I would say you should get a 100 amp alternator at the minimum. That's what I run, and it works well with my set up. I think the contour fans pull almost 40 amps at start up, so, even a stock 60 amp alternator would be pretty iffy.

Torsion bars I'd go with at least PST's 1.03's, if you're planning a more serious handling car Firm Feel's 1.06's or 1.12's (which is what I run) work well too. And you'll need Bilstein RCD's or Hotchkis shocks for any of those unless you hate your dental fillings and lumbar disks.

You absolutely should install subframe connectors at the minimum. Torque boxes would be very beneficial as well. And if you're looking at a handling car, some kind of foward supports (J bars or US Cartool inner fender supports) and a radiator support brace.

Doug's D453 headers will fit, so will TTI's, and I wouldn't bother spending the money on anything else. Those are both above the steering link, the other designs have tubes below the steering links and that isn't going to last on a lowered car. And they're not cheap enough to warrant buying a set to see if you smash them flat, most of them are more than half as much as the Doug's anyway, better to just do it right the first time.

I wouldn't worry about the clutch until you decide for sure on the transmission, because that will change.

Just my .02.

Now that's what I'm not getting then, I was under the impression a stroker kit tacked on extra iron to lengthen the cylinder in addition to the longer travel rods & crank. If you ask me though, aren't you risking more sideloading wear? Plus in general I'd like to stick to lower functional displacement, otherwise I'd yank the 440 from Gramp's motorhome and drop that **** in the Demon instead. If I really wanted to go cheap, I could also just yank the 318 from my Dakota, give it a light overbore, change of cam and heads. If I may ask, it sounds like you have a 340 stigma?

See, there's a suggestion I can go with. As long as the radiator mostly fits then I'm down for that plan (and as long as it isn't all gunked or dinged up, who knows with junkyard cars)

I knew an older alternator wasn't gonna cut it with this setup. I was shootin a lil high though for 130-140 amps Powermaster 8-47529: Upgrade Alternator Natural Finish | JEGS

See the ones on jegs only seem to go up to 0.920", the thicker ones are for the B bodies. Guess these are the PSTs 1.03" Torsion Bar - A Body And I figured I can move away from the KYB shocks on there eventually, but because those are there it's a lower priority (although I gotta admit, KYB must stand for "kill your back", going over the railroad tracks I thought the car was gonna split in half)

I don't know too much about this radiator support brace. Something I gotta fabricate?

These headers? Doug's Headers D453: Metallic Ceramic Coated Headers 1962-1974 Dodge/Plymouth 273-360 1-5/8" Tube Diameter | JEGS ceramic coated, that'll help with heat control

 

[72bluNblu]

Now that's what I'm not getting then, I was under the impression a stroker kit tacked on extra iron to lengthen the cylinder in addition to the longer travel rods & crank. If you ask me though, aren't you risking more sideloading wear? Plus in general I'd like to stick to lower functional displacement, otherwise I'd yank the 440 from Gramp's motorhome and drop that **** in the Demon instead. If I really wanted to go cheap, I could also just yank the 318 from my Dakota, give it a light overbore, change of cam and heads. If I may ask, it sounds like you have a 340 stigma?

There are only two differences really with the stroker. The crank, and the pistons. The rods are the same. The crank has a 4" stroke instead of 3.31" for the 318/340's, or 3.58" for the 360. The pistons then have a different pin height to adjust, and a shorter skirt length. You do increase the sideloading, but even with the 4" stroke the rod ratio isn't that bad, there are worse combinations out there. With a good block, it won't be an issue. The 4" stroke cranks have been around for awhile now, lots of people run them without issue. For price, you lose money on the crank, but most aftermarket rods don't cost that much more than refurbishing/resizing a stock set of rods with ARP bolts. Piston cost is about the same, and you're already planning aluminum heads that flow better.

I don't have a 340 stigma. I run one, I love it. But having said that, there's no reason to prefer a 340 over a 318 or a 360 for a non-numbers matching build. All they do is cost more. The historical significance associated with them had everything to do with them being a high-performance factory engine, if the 318 or 360 had ever come in a high compression, 4 barrel engine with a slightly bigger cam (like the 340's did) they would be just as revered. If I was starting with nothing, I'd buy a 360 block over a 340 every single time now. The 340 gets all the love because of what it was from the factory. A 360 rebuilt to the same specs will do just as well or better, and if you have to buy the block you can save hundreds going with the 360.

Honestly, I think the 408's are the way to go unless you go big block. The thing is that while you can build screamer engines that make a lot of power, you lose streetability. That's what I'm looking at with my 340. Its a strong engine, but mostly over 3k rpm. It's a beast between 3k- 6k. But on the street, that's not where you want your rpm's to be. I could make more horsepower with a 408 and the resulting build would still be easier to drive on the street.

See, there's a suggestion I can go with. As long as the radiator mostly fits then I'm down for that plan (and as long as it isn't all gunked or dinged up, who knows with junkyard cars)

A 26" radiator fits just fine. You don't even need to open up the radiator support for the larger radiator if you don't want to. All you need to do is add the new mounting holes. And if you do want to trim the radiator support it's just cutting about an inch off of either side of the radiator opening.

I knew an older alternator wasn't gonna cut it with this setup. I was shootin a lil high though for 130-140 amps Powermaster 8-47529: Upgrade Alternator Natural Finish | JEGS

If you go with a 130-140 amp alternator you'll absolutely have to bypass the alternator gauge and bulkhead connector. If you put that much power through the bulkhead connector you'll burn your wire harness to the ground, if not your car. But since that's a 1 wire alternator with an internal regulator maybe that's your plan. I've been running my Duster with the stock amp gauge and bulkhead connector using the 100 amp alternator. I did the same on my Challenger for 60k miles, but the Challenger doesn't have the same kind of draw because the fan on that one is still mechanical.

See the ones on jegs only seem to go up to 0.920", the thicker ones are for the B bodies. Guess these are the PSTs 1.03" Torsion Bar - A Body And I figured I can move away from the KYB shocks on there eventually, but because those are there it's a lower priority (although I gotta admit, KYB must stand for "kill your back", going over the railroad tracks I thought the car was gonna split in half)

You won't find any Mopar Performance bars bigger than .94" for the A-bodies, they haven't been making the larger sizes. You'll have to go aftermarket to go bigger than that. PST gives a FABO member's discount if you call them, and their 1.03's are a good rate if you're not planning autoX or anything like that. The only way you'll be happy with larger bars is without the KYB's. Those things are terrible. I ran my Challenger with 1.12" bars and KYB's for like 50k miles, changing to the Bilsteins was such a huge difference it was like a whole new car. KYB's are for garbage cans, not cars.

I don't know too much about this radiator support brace. Something I gotta fabricate?

No, US Cartool makes one that fits right up agains the stock lower support. I have a tubular brace on my car, but the source is no longer in business. Here's the US Cartool piece. 67-75 A-Body Core Support Stiffener

These headers? Doug's Headers D453: Metallic Ceramic Coated Headers 1962-1974 Dodge/Plymouth 273-360 1-5/8" Tube Diameter | JEGS ceramic coated, that'll help with heat control

Yup. Autozone is running a 20% discount right now, they will ship them to your door and you save a ton....http://www.autozone.com/exhaust/exh...656_5281?fromString=search&make=&model=&year=

 

[knote72]

There are only two differences really with the stroker. The crank, and the pistons. The rods are the same. The crank has a 4" stroke instead of 3.31" for the 318/340's, or 3.58" for the 360. The pistons then have a different pin height to adjust, and a shorter skirt length. You do increase the sideloading, but even with the 4" stroke the rod ratio isn't that bad, there are worse combinations out there. With a good block, it won't be an issue. The 4" stroke cranks have been around for awhile now, lots of people run them without issue. For price, you lose money on the crank, but most aftermarket rods don't cost that much more than refurbishing/resizing a stock set of rods with ARP bolts. Piston cost is about the same, and you're already planning aluminum heads that flow better.

I don't have a 340 stigma. I run one, I love it. But having said that, there's no reason to prefer a 340 over a 318 or a 360 for a non-numbers matching build. All they do is cost more. The historical significance associated with them had everything to do with them being a high-performance factory engine, if the 318 or 360 had ever come in a high compression, 4 barrel engine with a slightly bigger cam (like the 340's did) they would be just as revered. If I was starting with nothing, I'd buy a 360 block over a 340 every single time now. The 340 gets all the love because of what it was from the factory. A 360 rebuilt to the same specs will do just as well or better, and if you have to buy the block you can save hundreds going with the 360.

Honestly, I think the 408's are the way to go unless you go big block. The thing is that while you can build screamer engines that make a lot of power, you lose streetability. That's what I'm looking at with my 340. Its a strong engine, but mostly over 3k rpm. It's a beast between 3k- 6k. But on the street, that's not where you want your rpm's to be. I could make more horsepower with a 408 and the resulting build would still be easier to drive on the street.



A 26" radiator fits just fine. You don't even need to open up the radiator support for the larger radiator if you don't want to. All you need to do is add the new mounting holes. And if you do want to trim the radiator support it's just cutting about an inch off of either side of the radiator opening.


If you go with a 130-140 amp alternator you'll absolutely have to bypass the alternator gauge and bulkhead connector. If you put that much power through the bulkhead connector you'll burn your wire harness to the ground, if not your car. But since that's a 1 wire alternator with an internal regulator maybe that's your plan. I've been running my Duster with the stock amp gauge and bulkhead connector using the 100 amp alternator. I did the same on my Challenger for 60k miles, but the Challenger doesn't have the same kind of draw because the fan on that one is still mechanical.



You won't find any Mopar Performance bars bigger than .94" for the A-bodies, they haven't been making the larger sizes. You'll have to go aftermarket to go bigger than that. PST gives a FABO member's discount if you call them, and their 1.03's are a good rate if you're not planning autoX or anything like that. The only way you'll be happy with larger bars is without the KYB's. Those things are terrible. I ran my Challenger with 1.12" bars and KYB's for like 50k miles, changing to the Bilsteins was such a huge difference it was like a whole new car. KYB's are for garbage cans, not cars.



No, US Cartool makes one that fits right up agains the stock lower support. I have a tubular brace on my car, but the source is no longer in business. Here's the US Cartool piece. 67-75 A-Body Core Support Stiffener



Yup. Autozone is running a 20% discount right now, they will ship them to your door and you save a ton....http://www.autozone.com/exhaust/exh...656_5281?fromString=search&make=&model=&year=

I see what you're saying now about the stroker. But that poses me with a problem now, I was pretty deadset on the 340. Even though the 360 is a larger displacement and would make more torque, and the LA engines were all good engines, I hold no special feelings for it. I hear some others also do have a stigma with it, being released in the years as emissions and efficiency controls took hold and the only good run it had was in trucks to avoid the emissions choke. Gonna take some work to get me over the 340. I'd be more likely to build-up a 318 (rant incoming), I have a soft spot for that little motor, I had it in my first pickup and still have it ready to run anyday. After all these years, it's finally due for a rebuild anyways (plus those Aussies prove a lot of things can be coaxed with a little turbo). Heck, even clapped out it dragged my Demon over the mountains all the way from Boise, that alone deserves a repurpose! That engine alone made my truck way more reliable than most of the Ford garbage that passed through our possession, seemingly jetting by on their way to the junkyard. F150. F250. Taurus. Escort. Thunderbird ("the 4.6L is a great motor", my ***!). The Ranger is the only one able enough to pull its own weight, which is why it isn't on junkyard row (rant over). So if I did opt for other than the 340, I'd go for my ol 318 and spend the money on good top end and internals, and maybe a turbo setup. Oversquare all the way. In the near future though (when I'm not broke), if you do wanna sell your 340 I'll happily buy it.

Let's be honest here, I know absolutely jack about auto electrical. I know electrical basics, and can diagnose basic problems, but that's it. I did at least figure that the whole electrical system on the Demon would need to be redone, if I plan to add a proper stereo, EFI system and electric fans. Existing stuff functions ok, a few gauges like temp and gas level dead, but barely enough to support its own amperage. Again, that 140 was just an overestimation on my part, if my setup can get by on just 100 then awesome. No plans to drop in an amp and subs, that's for sure.

Not gonna lie, the price is a bit iffy for a fabricated piece of metal

If only all these deals didn't hit when I was broke, then again now probably isn't the time to go out and start buying stuff.

 

[moparmat2000]

I see a lot of posts on the 100 and above amp alternators in these old cars. Can somebody school me on this. Why does one need a 130 amp alternator in one of these cars anyways. I put a 50A in, and enlarged my output wire to 8ga marine grade based on the length of run required, and bypassed the bulkhead. I plan on running everything as LED for effiency, except the headlamps because i hate the hokey looking LED lamps, i plan on a small stereo, and no electric fan. I prob actually could have gotten away with a 35A alt, 10ga wiring, and the bypass.

Are you putting in EFI, a big booming system with a cinder block sized amp, and maybe a killer CB system where you want to talk to people several states away. Look at the power requirements for what that your planning on adding.

 

[moparmat2000]

As far as deals hitting. I am broke most of the time
I save a little at a time and patiently wait. When the deal i need hits, i jump on it.

 

[knote72]

I see a lot of posts on the 100 and above amp alternators in these old cars. Can somebody school me on this. Why does one need a 130 amp alternator in one of these cars anyways. I put a 50A in, and enlarged my output wire to 8ga marine grade based on the length of run required, and bypassed the bulkhead. I plan on running everything as LED for effiency, except the headlamps because i hate the hokey look LED lamps, i plan on a small stereo, and no electric fan. I prob actually could have gotten away with a 35A alt, 10ga wiring, and the bypass.

Are you putting in EFI, a big booming system with a cinder block sized amp, and maybe a killer CB system where you want to talk to people several states away. Look at the power requirements for what that your planning on adding.

The 130-140 was an overestimation on my part, I'm not big on electrical. The 100A I'd guess is more for wiggle room in conjunction with the more modern stuff.

Same with the LED stuff where possible, plus less often changing lights. The electric fan would be the most draw from any single part of my system. idk what the EFI draws exactly. A more modern starter would be a good idea, starter obviously draws no power from the alternator but one that demands less power means the alternator works less charging the battery.

 

[moparmat2000]

I would research and add up all your power needs. Keep in mind, you wont be running everything all the time. Elect fans and EFI would be your continuous draw items, along with lighting concidering you may be driving at night. Not sure what your stereo needs might be.

Elect fan and EFI will be the biggest draws. Using LEDs everywhere helps with lessening the power draw there.

I plan on a 6 speaker setup with a hidden audio setup. Basically its just a 4 channel amp box that plugs into a phone or mp3 player as the head unit. Dual 3.5s with bass blockers in the center dash opening, 4x6 in the kick panels and 6x9s in the rear deck. No amp. Car is a radio delete, so i want to keep it looking that way. Going to run flowmaster 40s to quiet it down. Should sound ok. So i can hear my tunes.

I am going carbureted, and mechanical clutch fan so my amp draw needs are less than yours. An 18" mechanically driven clutch fan with a proper shroud cools just as good as proper sized elect fans along with not having to run additional wiring, relays etc.

However I do recommend running a relay setup for your headlamps. This takes the strain off the stock wiring, and will allow you to run halogen sealed beams and have them burn brighter instead of going with more expensive HIDs.

I got a nice relay box setup i plan on using made by littlefuse. Its a sealed box, uses micro relays. And GM weatherpak terminals. Picked it up off evilbay. Its just taped in place. Car is in the mock up stage. I will be wiring it up, then pulling everything out for paint. I think it looks like it belongs right where i have it mounted.

 

[72bluNblu]

I see what you're saying now about the stroker. But that poses me with a problem now, I was pretty deadset on the 340. Even though the 360 is a larger displacement and would make more torque, and the LA engines were all good engines, I hold no special feelings for it. I hear some others also do have a stigma with it, being released in the years as emissions and efficiency controls took hold and the only good run it had was in trucks to avoid the emissions choke. Gonna take some work to get me over the 340. I'd be more likely to build-up a 318 (rant incoming), I have a soft spot for that little motor, I had it in my first pickup and still have it ready to run anyday. After all these years, it's finally due for a rebuild anyways (plus those Aussies prove a lot of things can be coaxed with a little turbo). Heck, even clapped out it dragged my Demon over the mountains all the way from Boise, that alone deserves a repurpose! That engine alone made my truck way more reliable than most of the Ford garbage that passed through our possession, seemingly jetting by on their way to the junkyard. F150. F250. Taurus. Escort. Thunderbird ("the 4.6L is a great motor", my ***!). The Ranger is the only one able enough to pull its own weight, which is why it isn't on junkyard row (rant over). So if I did opt for other than the 340, I'd go for my ol 318 and spend the money on good top end and internals, and maybe a turbo setup. Oversquare all the way. In the near future though (when I'm not broke), if you do wanna sell your 340 I'll happily buy it.

Let's be honest here, I know absolutely jack about auto electrical. I know electrical basics, and can diagnose basic problems, but that's it. I did at least figure that the whole electrical system on the Demon would need to be redone, if I plan to add a proper stereo, EFI system and electric fans. Existing stuff functions ok, a few gauges like temp and gas level dead, but barely enough to support its own amperage. Again, that 140 was just an overestimation on my part, if my setup can get by on just 100 then awesome. No plans to drop in an amp and subs, that's for sure.

Not gonna lie, the price is a bit iffy for a fabricated piece of metal

If only all these deals didn't hit when I was broke, then again now probably isn't the time to go out and start buying stuff.

Exactly, it's the 360's that have the stigma. They never released a hi-po 360 engine. If the factory had put out a 4 barrel 360 with a 340 cam in it no one would be so high on the 340's now. There's nothing magical about the 340's, they're basically just 318's with 22 more cubes and better heads. I just don't see wasting the dollars to pay for the reputation of a factory 340, when you're not building a factory 340. Because they cost 2-3 times as much as a 360, and 4 or 5 times as much as a 318. A 360 built the same as a 340 will win out every time. As for the 318, if you upgrade the internals enough you might as well go stroker for the costs involved. If you buy the big heads, better connecting rods and pistons all that's left is the crank, and you have to spend a chunk of what the stocker crank costs to turn the original. No replacement for displacement. You could go stroker on the 318 too, comes out around 390. I've always liked the idea of a turbo'd 318, but the problem is the fabrication work. If you're not really familiar with turbo's it's a problem, because there's no "kit". There are some shortcuts and you can do the searches on here, but most end in pain. There's just so much fabrication for the hot and cold pipes, and the routing sucks on an A-body. You'd be way money ahead building the stroker. Again, just my opinion. Guys have totally made the turbo work and work well, but it's a significant amount of work to do it right.

The 100 amp alternator will work. It's marginal for the stock bulkhead connector and amp gauge. I made sure all my connections were good and clean before I added mine, but the bypass is still the way to go.

The lower support brace from US Cartool is spendy, heck, all of their stuff is. But I look at it in terms of time. Like, how long will it take me to make this, and will it look that good? Usually their stuff wins if I consider making what I make at work, which is still a lot less than I'd pay a shop to make the stuff.

I would totally sell my 340. I'd just have to build a 408 first to replace it.

I see a lot of posts on the 100 and above amp alternators in these old cars. Can somebody school me on this. Why does one need a 130 amp alternator in one of these cars anyways. I put a 50A in, and enlarged my output wire to 8ga marine grade based on the length of run required, and bypassed the bulkhead. I plan on running everything as LED for effiency, except the headlamps because i hate the hokey looking LED lamps, i plan on a small stereo, and no electric fan. I prob actually could have gotten away with a 35A alt, 10ga wiring, and the bypass.

Are you putting in EFI, a big booming system with a cinder block sized amp, and maybe a killer CB system where you want to talk to people several states away. Look at the power requirements for what that your planning on adding.

It's the electric fans. The Ford Contour set up I run has a start draw of like 40 amps. It pulls less than that once it's running, but it's still like 30 amps. If nothing else is on maybe you can get away with a 60, but if you're blasting the stereo and have the headlights on, well, you're out of juice.

Mechanical fans are nice for their simplicity, but it's pretty awesome to only have the fans running when they need to be running. None of the various clutch options will do as well as the digital controller I run. Plus it's super nice to have the fans run for another minute or so after shut down in the summer. A properly set up mechanical system should work fine for pretty much everyone, but going electrical does have some nice perks. And the alternator is an easy deal anyway.

 

[moparmat2000]

I agree on the 360 statement. I had a neighbor building a 72 swinger, he kept on about putting a 340 in it. I told him a 360 built right would smoke a 340, and a 360 turned into a 408 stroker would smoke a 340 even worse. He just couldent get it out of his head saying that the 340 was better for some reason. Yep its essentially an overbored 318 with thicker walls, bigger valves, a 4bbl, and a hot cam.

US car tool rad support stiffener is a pricey piece, but if you can weld and fabricate, why not make your own out of 2x3 box steel like i did. Sure it costs you in time, but if your bucks down then use the time. I personally think my 2x3 box core support is probably way stronger than the us car tool add on to the stock support. I wanted to show a nice way to make corners with boxed steel rhat you may want to copy. I cut out for the radiator to set down in the new radiator lower support, then flipped the cut out piece, and used it to box the crossmember back in. Last pic shows it doesnt hang too much lower than the stock crossmember. Once painted black it wont be seen anyways. I also trimmed and fitted what was left of the stock lower support back in place.

 

[72bluNblu]

I agree on the 360 statement. I had a neighbor building a 72 swinger, he kept on about putting a 340 in it. I told him a 360 built right would smoke a 340, and a 360 turned into a 408 stroker would smoke a 340 even worse. He just couldent get it out of his head saying that the 340 was better for some reason. Yep its essentially an overbored 318 with thicker walls, bigger valves, a 4bbl, and a hot cam.

US car tool rad support stiffener is a pricey piece, but if you can weld and fabricate, why not make your own out of 2x3 box steel like i did. Sure it costs you in time, but if your bucks down then use the time. I personally think my 2x3 box core support is probably way stronger than the us car tool add on to the stock support. I wanted to show a nice way to make corners with boxed steel rhat you may want to copy. I cut out for the radiator to set down in the new radiator lower support, then flipped the cut out piece, and used it to box the crossmember back in. Last pic shows it doesnt hang too much lower than the stock crossmember. Once painted black it wont be seen anyways. I also trimmed and fitted what was left of the stock lower support back in place.

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That's some really nice work!

And I'm sure that is stiffer than the US Cartool piece, having installed one on my Dart. But knowing how long that would have taken me to fabricate, I'd still be money ahead to buy the US Cartool piece.

 

[moparmat2000]

At the time i did it, i had a lot of time, not so much in the cash department, and i had leftover tubing from my homemade subframe connectors. So the money had already been spent on the tubing. Took me a saturday and a sunday to do. It is waaay stiffer. I actually stood all 240 lbs of me on it, and it didnt bend.

 

[knote72]

Exactly, it's the 360's that have the stigma. They never released a hi-po 360 engine. If the factory had put out a 4 barrel 360 with a 340 cam in it no one would be so high on the 340's now. There's nothing magical about the 340's, they're basically just 318's with 22 more cubes and better heads. I just don't see wasting the dollars to pay for the reputation of a factory 340, when you're not building a factory 340. Because they cost 2-3 times as much as a 360, and 4 or 5 times as much as a 318. A 360 built the same as a 340 will win out every time. As for the 318, if you upgrade the internals enough you might as well go stroker for the costs involved. If you buy the big heads, better connecting rods and pistons all that's left is the crank, and you have to spend a chunk of what the stocker crank costs to turn the original. No replacement for displacement. You could go stroker on the 318 too, comes out around 390. I've always liked the idea of a turbo'd 318, but the problem is the fabrication work. If you're not really familiar with turbo's it's a problem, because there's no "kit". There are some shortcuts and you can do the searches on here, but most end in pain. There's just so much fabrication for the hot and cold pipes, and the routing sucks on an A-body. You'd be way money ahead building the stroker. Again, just my opinion. Guys have totally made the turbo work and work well, but it's a significant amount of work to do it right.

The 100 amp alternator will work. It's marginal for the stock bulkhead connector and amp gauge. I made sure all my connections were good and clean before I added mine, but the bypass is still the way to go.

The lower support brace from US Cartool is spendy, heck, all of their stuff is. But I look at it in terms of time. Like, how long will it take me to make this, and will it look that good? Usually their stuff wins if I consider making what I make at work, which is still a lot less than I'd pay a shop to make the stuff.

I would totally sell my 340. I'd just have to build a 408 first to replace it.



It's the electric fans. The Ford Contour set up I run has a start draw of like 40 amps. It pulls less than that once it's running, but it's still like 30 amps. If nothing else is on maybe you can get away with a 60, but if you're blasting the stereo and have the headlights on, well, you're out of juice.

Mechanical fans are nice for their simplicity, but it's pretty awesome to only have the fans running when they need to be running. None of the various clutch options will do as well as the digital controller I run. Plus it's super nice to have the fans run for another minute or so after shut down in the summer. A properly set up mechanical system should work fine for pretty much everyone, but going electrical does have some nice perks. And the alternator is an easy deal anyway.

Now here's where I'll REALLY scrutinize your point and ask, what's your long-term cost? There's no replacement for displacement, sure, but the same applies at the pump. Sure it's slim margins in gas mileage, but I could argue the same about 20 cubes. Cost is your prevailing point for the 360, and yes it makes more torque (not by too much, since it's an oversquared block like the 340 until you do a stroker), but that cost automatically goes up over time when you're gassing up more displacement. Even on mild tune and efi the 5.9l blocks hardly got higher than low teens, though a few rumors in the ballpark of 20mpg linger (no doubt on a super lean setup, robbing any power advantage).

Aftermarket support has often been a shortcoming for the mopar realm, nothing new. We don't hardly get the same support the ford or chebby guys do, unless it's for a 440 or the hemi.

If I can't find a 340 block then I'll bite and look for an LA360 (gonna be hard sifting thru the sea of 5.9l magnums). It's not that I myself have 360 stigma, it's just that when someone suggests a 360 I get the same feeling some Chevy guys get when they hear the words "just drop an LS in it"

I'm within a day trip's distance of you 72blu, so if you put the 340 up for sale in the future then let me know (or if you're open to trade for a 440 block.....).

 

[knote72]

Resurrecting this thread with a quick question: have you guys ever heard of throwing a timing tensioner on a small block? I was watching a video and a guy commented about getting a timing tensioner for the 90s 3.9L V6 and throwing it in any one of the small blocks to reduce long term timing slop.

Thoughts?

 

[moparmat2000]

I thought about that myself. As a matter of fact cloyes makes a stock replacement V6 tensioner for not too much coin, about $30, and mopar performance used to offer theirs for a V8 app in their catalog. I think the problem is that the nylon tensioner shoe is not wide enough if using a beefier and wide double roller chain to allow it to ride against the full width of the chain. I believe it was designed for use with stock type single roller chain sets. Now if building a mild small block with a stock single roller chain the tensioner could be valuable since those develop chain stretch and slop pretty early.

 

[knote72]

I thought about that myself. As a matter of fact cloyes makes a stock replacement for not too much coin, and mopar performance used to offer theirs for a V8 app in their catalog. I think the problem is that the nylon tensioner shoe is not thick enough if using a beefier double roller chain. I believe it was designed for use with stock type single roller chain sets. Now if building a mild small block with a stock single roller chain the tensioner could be valuable since those develop chain stretch and slop pretty early.

Yeah I know I found it right here http://www.jegs.com/i/Cloyes/220/9-5387/10002/-1 well I was planning on a double roller so that poses a problem. Again, from how it sounds they were originally used in the V6s

 

[moparmat2000]

Stock timing chains were a cheaper made deal, and the tensioner certainly helps keep the timing true. Its a great idea. I am planning on a mild 318 to use in my car, and then transfer eventually into my sons car, i will likely use an aftermarket higher grade single roller , and V6 tensioner in it. My 408 will have a beefier double roller setup.

 

[knote72]

To shift over to looking ahead at the trans work, was wondering what thoughts would be on this article 1969 Dodge Dart - Mopar A-Body Tech Easy 6-Speed Manual Swap

Found this on American Powertrain's site 1967-76 A-Body Pro-Fit 6-Speed seems it's a popular enough swap to warrant a kit. Might make the swap easier?

On the other hand I was also wondering, what separates the current Tremec T56 from the T56 that was in the 90s Viper? Other than it was originally developed by Borg-Warner then carried over to Tremec? Because I heard about a guy up in Portland selling a few low-mileage Viper transmissions for $1700 a piece, I'm still a ways away from that pricewise but if they're reasonably compatible then I could just try to source the right parts and go the cheaper-but-harder route. That'd cut down the cost of buying a brand new kit with a T56.

 

[knote72]

If only........

 

[moparmat2000]

Why not build a 360 with a stroker kit to make it a 408?
340s were good for their time, and still are to a point. They had a lot of hot roddy stuff but were essentially a large bore 318. Car companies always do **** on the cheap if they can get away with it.

In the case of the 273, 318, 340 i believe they all share the same crank stroke and same length rods, and only the bore is different.

360 shares the same length rods, has the bigger bore like the 340 but a longer stroke.

The 340s claim to fame was it could wind up quickly to 6,000 rpm. This made em a 1/4 mile contender. If your planning on a 6 speed manual, modern upgrades and not really going for an original resto because of the vin which will always say its a slant 6, then id recommend to, buy a 360, add an eagle or scat stroker kit and be done with it. Scads of HP compared to the 340, same amount of money spent.

I payed $200 for a mid 70s 360 truck engine and i sold off what i didnt need. Stroker kits w forged cranks for SBM are coming down a bit in price. You can find em for around $1,500 now.

Magnum 360s are plentiful in junkyards now. Stroker kits are the same as for LA 360s. And they are a roller cam engine. Engine quest sells an iron monster magnum head. All new casting eliminates the cracks associated with the stock heads. You can buy em machined for an LA intake bolt pattern, or for a magnum head bolt pattern. I believe they are machined for 2.02 - 1.60 valves. Part numbers are CH318A, and CH318B part number determines how its machined for an intake manifold. Also 5 bolt valve covers will work on the 10 bolt magnum heads.

As far as a manual goes, i cant help you there. I set mine up for an A-833 OD box. I will likely swap that out later on for a passon 5 speed.