Beginner's Bucks-Down /6 Build...Suggestions Welcome

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mopar68a

Dare to be different :D
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Hello all. This is a great site. I have spent hours browsing here and at /6.org and have gathered a treasure trove of information. That's the hard part... so many good ideas, it's hard to choose exactly what to do.

I am working on getting the car now. I hope for a 68 Dart 270 more door, but I will be OK with a 70-74 Dart Custom more door. Running or not, as long as it's a solid foundation for a good build and is not wrecked. Running preferred, though. I'd like to drive it during the week and wrench on it on the weekends.

As I said in the title, it's a bucks-down build. I'm planning to do this over a 3-5 year timeframe and I want to use as many used / junkyard / rebuilt parts as I can. There is much I can do myself, and much I'm willing to learn from others concerning this build.

I'd like the car to be street-only, run a bit faster, handle, and stop a bit better than it did when new. With that in mind, based on what I have learned, I have come up with the following tentative build...

Engine= '72-'74 head if '68-'71, '73+ electronic ignition with orange box and Pertronix coil if '68-'72, NGK ZFR5N-3459 plugs, '71+ stock cam if '68-'70, Offy intake with 2v adapter plate, Holley 2300 350cfm 2bbl., stock manifold > 2.25 headpipe and Y-pipe > 2.25in / 2.5out muffler > 2.5 tailpipe.

Transmission= B&M Shift Improver kit

Rearend= '73-'76 8.25 if '68-'72, SureGrip and 3.23:1.

Suspension= OEM HD / Rallye with front sway bar.

Brakes= '73-'76 LBP front disc / rear drum if '68-'72.

Steering= '87-'94? Dodge Dakota 2WD manual or power rack and pinion.

Wheels and Tires= 14x6 steelies with dog-dish caps, Goodyear 205/70R14 or 215/70R14.

Other Mods (for later)= Holley 390cfm 4v #8007, Dutra Duals?, 2"? dual-exhaust, Head= 318 valves, 340 springs, street port and gasket match, milled .050 for 9.0:1CR or .090 for 9.5:1CR, Oregon Cams #125? 212/206, 415/399, later lockup converter A904 TorqueFlite?.

What can I expect, over stock, with this build? Suggestions for changes welcome. I know there are things I have overlooked or not considered. Thanks for your time and consideration.
 
You've done yur homework I see.

I think on your initial build you should go ahead and do a little port work on the head or at least polish the ports.

Also in your longtime build, make sure you CC the head and calculate compressio before any milling.
 
/6 Matt said:
You've done yur homework I see.

I think on your initial build you should go ahead and do a little port work on the head or at least polish the ports.

Also in your longtime build, make sure you CC the head and calculate compressio before any milling.
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Noted. Thanks much. It's details like those you mention that count. I want to do it right the first time and not miss a step. :-D
 
All my comments here are directed at improving handling. Personally I would not bother with the larger rear end until or if you ever go to a V8; the smaller rear should be quite adequate with the mild and wilder /6 engines you list, and will be lighter, which means it will handle better over rough surfaces, due to less weight for the shocks to control. The posi wil lbe a big improvmewnt so go for that. Use high quality gas shocks like Bilsteins. Similarly, I would use AL wheels, not steel; the weight difference is huge for rough surface handling. Mono-leaf rear springs would be a good improvment but that IMO should come last unless they are cheap. The front torsion bar spring system is pretty good so I would not touch that.

The use of just a heavier sway bar is typically not optimum for handling; production car designs put the front sway bar in first and heavier, so that the front end will push out in hard cornering before the rear end gets loose That is best of the average driver who can't anticipate and handle a loose rear car, but is not optimum for handling. So a rear anti-sway bar is in order for best handling. (As a later item.)

Brake combo of disc front/drum rear will be adequate for all but the most demanding paved surface driving. The largest drum brakes are best, simply for heat dissipation, and using a good semi-metallic compound up front and a heavy police interceptor level of rear shoe compound will be good. Brake bias can be adjusted with compound changes if you ever get to that, but most people don't go there for street driving, unless they have a lot of rear lock up in wet conditions. So that's ususally not too important.

The one drivetrain comment I will make is on the trannie; if you ever could get the 4 speed OD trannie that came in the Dart Lights and Plymouth Feather Duster, you would be really happy with the gas mileage increase with the 0.83 ratio OD 4th gear. There may be other good trannie conversions out there with an OD; I am not up to speed on those. If you are out for spirited street driving, a manual will add a whole new dimension to that.

Good luck! Sounds like fun!

(BTW, my race backround it rally, and we put in all sorts of effort for rough handling improvements; those same things make a car very predicable and allows much more aggressive handling for street use.)
 
nm9stheham said:
All my comments here are directed at improving handling. Personally I would not bother with the larger rear end until or if you ever go to a V8; the smaller rear should be quite adequate with the mild and wilder /6 engines you list, and will be lighter, which means it will handle better over rough surfaces, due to less weight for the shocks to control. The posi wil lbe a big improvmewnt so go for that. Use high quality gas shocks like Bilsteins. Similarly, I would use AL wheels, not steel; the weight difference is huge for rough surface handling. Mono-leaf rear springs would be a good improvment but that IMO should come last unless they are cheap. The front torsion bar spring system is pretty good so I would not touch that.

The use of just a heavier sway bar is typically not optimum for handling; production car designs put the front sway bar in first and heavier, so that the front end will push out in hard cornering before the rear end gets loose That is best of the average driver who can't anticipate and handle a loose rear car, but is not optimum for handling. So a rear anti-sway bar is in order for best handling. (As a later item.)

Brake combo of disc front/drum rear will be adequate for all but the most demanding paved surface driving. The largest drum brakes are best, simply for heat dissipation, and using a good semi-metallic compound up front and a heavy police interceptor level of rear shoe compound will be good. Brake bias can be adjusted with compound changes if you ever get to that, but most people don't go there for street driving, unless they have a lot of rear lock up in wet conditions. So that's ususally not too important.

The one drivetrain comment I will make is on the trannie; if you ever could get the 4 speed OD trannie that came in the Dart Lights and Plymouth Feather Duster, you would be really happy with the gas mileage increase with the 0.83 ratio OD 4th gear. There may be other good trannie conversions out there with an OD; I am not up to speed on those. If you are out for spirited street driving, a manual will add a whole new dimension to that.

Good luck! Sounds like fun!

(BTW, my race backround it rally, and we put in all sorts of effort for rough handling improvements; those same things make a car very predicable and allows much more aggressive handling for street use.)
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Noted. Thanks much for the details you included with your suggestions. I do hope to have fun with and enjoy this car for years to come. Learning, wrenching, driving, and surprising people.

I should explain the reason for the larger rearend for the '68 or '70-'72. The main reason I chose that was so I could use the LBP wheels front and rear. And it would seem easier to swap in the whole brake system instead of mating the later front brakes to the earlier rear brakes. As for aluminum wheels vs steelies, I agree. But the main reasons for the steelies are looks and cost. If I do end up going to aluminum wheels later, they would be 14x6 MoPar Rallyes. As for the transmission, I prefer auto over stick, as this car will be both a dd and a cruiser.
 
the 7 1/4 rear isnt adequate for a lawn mower let alone a slant. i went through 4 of them behind a stock slant before i got my 8 1/4. if you plan on doing anything more than cruising get a better rear. the sure grip 7 1/4 might hold up but the open ones arent worth diddly.
 
RustyPlymouth said:
the 7 1/4 rear isnt adequate for a lawn mower let alone a slant. i went through 4 of them behind a stock slant before i got my 8 1/4. if you plan on doing anything more than cruising get a better rear. the sure grip 7 1/4 might hold up but the open ones arent worth diddly.
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I second this right here^^^ I've personally blown up a 7-1/4" with a stock slant and I've heard of and seen others do the same. Get a later 8-1/4" with bbp and youll be miles ahead of the game. 3.23 gearing would be a good compromise in your setup.
 
A few more things to consider too. Make sure if you use a "stock" distributor that you recurve it. I think optimal advance curve is somehing like 12 btdc initial, total 32 btdc all in by 2500 rpm. Not sure on that though, talk to 805moparkid and he can set you straight in that dept.

And another thing

Go to this page
http://www.slantsix.org/forum/viewtopic.php?t=38446
Scroll down to wher it says "mini starter, more mini starter and even more ministarter" and read all that info. As you can see by my signature I got my starter from a '96 Dakota and mine was free sitting in my yard. By far one of the best improvements made on my car. Its lightweight and smaller so its easier to work on and all I gotta do is jist about bump the key and that starter whips my motor around. My Dart starts in one revolustion when it aint cold as hell.
 
Well i see where you are and where you want to go. My 2cents is this, the 4 barrel will get more power and better mpg than the 2 barrel, so why waste the time to get all the super expensive super six junk to KNOW you want a 4 barrel... do it once.

Get an offy as you said, factory ports will have good velocity, port match to the head after porting and smooth edges in the intake. For the carb there were 450cfm holley's back in the day with vac or mechanical secondaries, i like mechanical.

On the cam yes the 70's cam is better, but it sucks... slants have a long stroke so it eats up duration, i would be about 210-220 @ .050 duration on a 110-108LSA, alot more pep and better mpg/power where you want it

on the head plan on .110 off the bat, my 68 motor with flat tops was .177 in the hole with 56cc chambers. With the mill i think i was at 46cc's and a 9:1 comp. That said if your pulling the motor down take it all off the block which will benefit over head milling. On the valves the 318 valves take work with the rocker sweep where as the enginebuilder valves (1.70/1.44) off ebay work with minimal work and will support you just fine. On the head have the valves and guides "roughed in" then port/ have it ported to match the factory gasket and have good bowl work done.

On ignition i like an MSD street fire with blaster II or electronic ign with a petronix 60KV E-coil (3ohm) with ballast bypass. Matt was close on the curve, 12-16initial @ 750rpm, 30* total mechanical by 2500. You may be able to get away with the VC-208 vacuum can at about 5 turns out.

if i missed anything throw it out there.

Oh on the rear, 8.25 with a 3.21 gear works well, about 3000rpm's @ 65mph with a 24.5" tire, so using a taller 26 or even 27" tire will bring those rpms down about 3-500rpm which is where that slant is going to want to be.
 
Interesting comment on the axles. I drove 7-1/4" rear axles in 3 cars for over 200k miles and I don't spare the aggresssion on the throttle, and never had a lick of rear axle trouble. I suspect those blowing them are doing something hard or are starting with used ones from the j-yard that had problems to begin with. A good 7-1/4' should take a /6 no problem. You can get the large bolt pattern in all 3 axles.

The comment about the lighter rear axle is for keeping unsprung weight as low as you can for rough surface handling; live rear axles are never great but adding more weight makes poor handling worse. The brake and LBP swap all at once DOES make sense.

I am in the Appalachians and rough surface handling and handling in general are important if you drive on the roads rapidly from A to B. All of this info is suggestions and ideas and IMO, the OP should decide what he will use the car for; if all the roads in his area are very smooth, then the lighter axle wieght is of little value.

I don't see an issue with a manual floor shift trannie for DD.....?? If you are not drag racing, the manual will be a lot better aggressive driving trannie; the ability to use the rear braking of the engine through a manual in a RWD car will allow you do things in throwing the car about and taking advantage of weight transfer diving into corners that you cannot ever do in an auto (unless it is one of the new Challenger auto trannies). If you have raced a manual trannie car, it becomes obvious.

But, again these are just ideas and highlighting different aspects of performance and you get to make the decisions. I just like being able to keep up with a Porsche in twisty mountain roads; the look on their faces at the first stop when you have literally run them down in your better HP Detroit iron with the good handling package is priceless!
 
I have also had several 7 1/4 in various Darts and never had a lick of problem. I take care of my stuff though cause I have to work for every bit of it if that says anything.
 
well you can stay with a 7.25 and look for parts, like gears and carriers (good luck) or upgrade to a 8.25 and have many gear choices, a couple carrier choices, and the ability to use jeep rear discs or any 8.75/D60 brakes.
 
nm9stheham said:
Interesting comment on the axles. I drove 7-1/4" rear axles in 3 cars for over 200k miles and I don't spare the aggresssion on the throttle, and never had a lick of rear axle trouble. I suspect those blowing them are doing something hard or are starting with used ones from the j-yard that had problems to begin with. A good 7-1/4' should take a /6 no problem. You can get the large bolt pattern in all 3 axles.

The comment about the lighter rear axle is for keeping unsprung weight as low as you can for rough surface handling; live rear axles are never great but adding more weight makes poor handling worse. The brake and LBP swap all at once DOES make sense.

I am in the Appalachians and rough surface handling and handling in general are important if you drive on the roads rapidly from A to B. All of this info is suggestions and ideas and IMO, the OP should decide what he will use the car for; if all the roads in his area are very smooth, then the lighter axle wieght is of little value.

I don't see an issue with a manual floor shift trannie for DD.....?? If you are not drag racing, the manual will be a lot better aggressive driving trannie; the ability to use the rear braking of the engine through a manual in a RWD car will allow you do things in throwing the car about and taking advantage of weight transfer diving into corners that you cannot ever do in an auto (unless it is one of the new Challenger auto trannies). If you have raced a manual trannie car, it becomes obvious.

But, again these are just ideas and highlighting different aspects of performance and you get to make the decisions. I just like being able to keep up with a Porsche in twisty mountain roads; the look on their faces at the first stop when you have literally run them down in your better HP Detroit iron with the good handling package is priceless!
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Good points. I plan to use the car as a dd to and from work and in general. The cruising will be mostly back roads on the weekends when the car isn't being wrenched on. I live near Atlanta, GA, just Southeast of Decatur and the roads are mostly flat with a few good hills here and there. I prefer an auto over stick because, though I know how to drive both, my bf and my friends don't. So it's a concession to them.
 
805moparkid said:
well you can stay with a 7.25 and look for parts, like gears and carriers (good luck) or upgrade to a 8.25 and have many gear choices, a couple carrier choices, and the ability to use jeep rear discs or any 8.75/D60 brakes.
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Yet another good reason to upgrade the rearend. As for the tires you referenced earlier, what is the largest size I can put on the car without compromising safety, handling, and design limitations?
 
Here is a car I would buy, if it didn't have so much rust. It looks almost like someone tried to paint over it. So I'm still looking...

http://www.ebay.com/itm/Dodge-Dart-Base-/221362677183

And look at what they did to the door panels and kick panels. Butchery, just for bling speakers. Jeez. I'd rather do Custom Autosound's Secret Audio SS or something else in their line that is designed for the Dart and designed to blend in, work with the original interior design.
 
Sorry to ask this but if you are going to all of this why not a 2 door? I know there are lots of nice four doors on here but the 2 door is more desirable and bring a better resale in my opinion. But it is just my opinion.
 
dartnabout said:
Sorry to ask this but if you are going to all of this why not a 2 door? I know there are lots of nice four doors on here but the 2 door is more desirable and bring a better resale in my opinion. But it is just my opinion.
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No need for sorry. It's a valid question and a good point. The main reason is preference. I like being different. But I also need the extra space and easier access. It's also cheaper for me for insurance. I like the 2-door Dart GT's and Swingers. My Mom had a '71 318 Swinger. My Dad had a '68 Dart 4-door junkyard refugee. I remember helping him work on both.
 
Based on SlantSixDan's post here

http://www.slantsix.org/forum/viewtopic.php?t=44170

"I like my cars quiet, so I get my exhaust unrestriction by using a larger-than-stock, stock-type muffler. The stock unit was really tiny, with 1¾" inlet and 1½" outlet, in a 3" × 7" body. Tiny! You can go to a much larger '95 Chev Caprice item with 2¼" inlet and outlet in a 4" × 9" body. MUCH better flow and it'll have a nice note to it, but it'll still be quiet and drone-free."

I like the idea he put forward concerning muffler choice, though I'd rather not use a GM part.
 
mopar68a said:
Yet another good reason to upgrade the rearend. As for the tires you referenced earlier, what is the largest size I can put on the car without compromising safety, handling, and design limitations?
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only way your going to "compromise safety" is if you run a slick in the rain or run old/wore out tire. Almost anything else is an upgrade. As far as size something you'll learn is we push the boundries from stock, guys are up to 20" rims, thousands of hp, super fast, super low. So when you say "without compromising safety, handling, and design limitations?" your just saying what is stock. Your not after stock as you stated, you want to be different. So that means you set a goal and make it happen, either you learn, you pay, or you dont.

Before you buy a car you need to list out what it needs to do (10/15/20/25mpg?, pump gas, breaks in to the 14/13/12/11/10/9's at the strip, autoX) and what you dont want it to do (loud, lots of maintenance, whatever)

mopar68a said:
Based on SlantSixDan's post here

http://www.slantsix.org/forum/viewtopic.php?t=44170

"I like my cars quiet, so I get my exhaust unrestriction by using a larger-than-stock, stock-type muffler. The stock unit was really tiny, with 1¾" inlet and 1½" outlet, in a 3" × 7" body. Tiny! You can go to a much larger '95 Chev Caprice item with 2¼" inlet and outlet in a 4" × 9" body. MUCH better flow and it'll have a nice note to it, but it'll still be quiet and drone-free."

I like the idea he put forward concerning muffler choice, though I'd rather not use a GM part.
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yea slant six dan is against it if its not stock, where as running a 2.25" exh into a DRONE FREE flowmaster super 50 Delta and 2.25 or 2.5" to the bumper will net more gains.

make your list before you drop a cent and then pick the car and build it that way. FYI the cost of a more door vs 68 Dart 270 is nothing, they cost the same to register and insure...
 
Here is a link to my 66 Valiant slant six build.
http://slantsix.org/forum/viewtopic.php?t=11218&postdays=0&postorder=asc&highlight=low+buck&start=0

Another rear to consider to replace the 7 1/4 is a Ford 8 inch. You need to hunt a little, as it needs to be from a early mustang, comet, also some others, They are like a 9 inch with a drop out center, but less expensive then a Mopar 8 3/4. Parts are readily available. You need the rear from a V-8, as they have 5 on 4.5 bolt pattern (6 cyl rears were 4 bolt). The 8 inch Ford is almost a bolt in conversion for an "A".
I found a 4.10 locker pumpkin at a swap meet for $200, and a drum to drum rear in a salvage yard for $100. Can't beat that price with a stick.
 
Welcome to the world of "Slant Sickness" ! Sounds like you have a plan, Take your time and find the best car you can afford. Stay away from rust issues as that will eat up any budget fast. Spend your money on suspension/brake up grades for safety first(only a suggestion).Then get into the driveline work. And last comment,,I really don't think you need to open up a can of worms by trying to do the Dakota rack. Just my thoughts... Most of all Have Fun !
 
Main problem with slant 6 is head flow, fully ported they only flow as much as a stock 273/318 port. A fully built $$$$$ NA /6 at best will cracked 300 hp most are probably in the 150-250 hp range.
 
805moparkid said:
only way your going to "compromise safety" is if you run a slick in the rain or run old/wore out tire. Almost anything else is an upgrade. As far as size something you'll learn is we push the boundries from stock, guys are up to 20" rims, thousands of hp, super fast, super low. So when you say "without compromising safety, handling, and design limitations?" your just saying what is stock. Your not after stock as you stated, you want to be different. So that means you set a goal and make it happen, either you learn, you pay, or you dont.

Before you buy a car you need to list out what it needs to do (10/15/20/25mpg?, pump gas, breaks in to the 14/13/12/11/10/9's at the strip, autoX) and what you dont want it to do (loud, lots of maintenance, whatever)



yea slant six dan is against it if its not stock, where as running a 2.25" exh into a DRONE FREE flowmaster super 50 Delta and 2.25 or 2.5" to the bumper will net more gains.

make your list before you drop a cent and then pick the car and build it that way. FYI the cost of a more door vs 68 Dart 270 is nothing, they cost the same to register and insure...
Click to expand...

"So that means you set a goal and make it happen, either you learn, you pay, or you dont."
True, that. With cars, and in life overall.
I should clarify what I meant by "design limitations". I want the tire / wheel combination to look like it belongs there. No bigger wheels and rubberband tires or overstuffed wells. Say maybe 15x7 and 215/75R15 maximum.
I want the car to maintain an average of 18-22mpg, run pump gas, and to not be overly loud. As for the muffler, maybe a Flowmaster DeltaFlow. I don't mind a bit of extra maintenance. I can do most of that myself. I'll need to investigate the insurance costs further.:-D
 
Charrlie_S said:
Here is a link to my 66 Valiant slant six build.
http://slantsix.org/forum/viewtopic.php?t=11218&postdays=0&postorder=asc&highlight=low+buck&start=0

Another rear to consider to replace the 7 1/4 is a Ford 8 inch. You need to hunt a little, as it needs to be from a early mustang, comet, also some others, They are like a 9 inch with a drop out center, but less expensive then a Mopar 8 3/4. Parts are readily available. You need the rear from a V-8, as they have 5 on 4.5 bolt pattern (6 cyl rears were 4 bolt). The 8 inch Ford is almost a bolt in conversion for an "A".
I found a 4.10 locker pumpkin at a swap meet for $200, and a drum to drum rear in a salvage yard for $100. Can't beat that price with a stick.
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True, that. Good price. I like the way you included the costs of parts in your thread. Nice car, too. I prefer doing an 8.25 from another A-Body. How much, on average, does the Ford rearend cost vs the A-Body 8.25? And would mating the Ford rear brakes to the MoPar front brakes be a problem?
 
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