318 Build? Help!

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MopaR&D said:
3/4-ton pickup truck (heavy), full-time 4x4 and 727 trans, D44/D60 axles, aerodynamics of a refrigerator... lots of parasitics to work against by the time the power gets to the road. Agree 1000% the performance will be far better if the focus is on bottom-end and mid-range torque instead of a peak HP number.
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I agree too but engines that make greater 3500-5000+ power tend good peak power too.

The problem is keeping as much 1500-3500 rpm power as possible while gaining 3500-5000+ rpm power, since it's far easier to lose in this range, than gain over the basic hop ups.
 
MopaR&D said:
What didn't you like about the '73 360? My '72 D200 (3.54 gears and 33" tires) has a mostly-stock 360 and it has plenty of torque although the RPM range is limited, runs out of breath around 4000 RPM. I don't dislike it but then I haven't driven a truck with a 340 or Cummins.

To the OP, I like milder engines in trucks. Compression no more than 9-9.5:1 to be able to run regular gas (since mileage will be terrible no matter what), milder cam to not require a higher-stall converter which will slip and build heat when pulling loads. Better heads won't hurt but will improve performance mostly just at higher revs. With a theoretical top speed of say 75 mph (you said you don't intend to go much over 60), there isn't much need for more than about 300 HP, if that. 300 is a very doable number for a 318 with over 9:1 compression, good heads/intake (Performer RPM...?) and a realistic mild performance cam. I think those 596 heads would work fine.
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I just never had any luck with 360's . Melted many pistons with a stock bottom end. Never had any that impressed me when it came to endurance. Smaller mains , Externally balanced, junk pistons, small main caps like 318 but longer stroke, That never made any sense, I would rather build a 318 then a 360. I had 408's and 416's World of difference . This is just my opinion . A stock 340 does not compare to a 360 in any vehicle. Everything is stronger in a 340 and easier to intermix with a 318 drive line. Let me know how easy it is to find a 360 flywheel or a good balanced damper for replacement in a truck or car with a 360.
 
Oldmanmopar said:
I just never had any luck with 360's . Melted many pistons with a stock bottom end. Never had any that impressed me when it came to endurance. Smaller mains , Externally balanced, junk pistons, small main caps like 318 but longer stroke, That never made any sense, I would rather build a 318 then a 360. I had 408's and 416's World of difference . This is just my opinion . A stock 340 does not compare to a 360 in any vehicle. Everything is stronger in a 340 and easier to intermix with a 318 drive line. Let me know how easy it is to find a 360 flywheel or a good balanced damper for replacement in a truck or car with a 360.
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Smaller mains? The main bearings in a 360 are bigger in diameter than the 273,318 and the 340. Melted pistons sounds like a serious detonation problem.
 
shittyslant6 said:
Well, it's just desktop dyno 5, I believe and I know it's within 8-12% accuracy.
I think it will make that much because it's going to spin to 7000+, and surprisingly the speedmasters flow exceptionally well for what they are.

But pertaining to this thread; even if it does not make the calculated power the program says; this combo at LEAST make more than enough torque and horsepower for OP's similar build to have fun with.
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I don’t mean to poop in your cheerios but that’s a 260-280hp combo at best. And unless you are very good (read: precise) at setting up the valvetrain there’s no way it’s going to spin “7000+”, and there’d be no reason to spin it that high anyway because with a 216@050 cam on 318 inches it’ll be all done making power well before 6200. Build it, tune it, and stick it on a dyno, if I’m wrong I will gladly accept that, but I don’t think I am.
 
TT5.9mag said:
I don’t mean to poop in your cheerios but that’s a 260-280hp combo at best. And unless you are very good (read: precise) at setting up the valvetrain there’s no way it’s going to spin “7000+”, and there’d be no reason to spin it that high anyway because with a 216@050 cam on 318 inches it’ll be all done making power well before 6200. Build it, tune it, and stick it on a dyno, if I’m wrong I will gladly accept that, but I don’t think I am.
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You sure? Every guy that ever owned a 289 swears they spin to 9k even stock.... a 318 should be able to do it :)

BTW.. why would you want a truck to spin over like 5500-6k anyway?
 
TT5.9mag said:
I don’t mean to poop in your cheerios but that’s a 260-280hp combo at best. And unless you are very good (read: precise) at setting up the valvetrain there’s no way it’s going to spin “7000+”, and there’d be no reason to spin it that high anyway because with a 216@050 cam on 318 inches it’ll be all done making power well before 6200. Build it, tune it, and stick it on a dyno, if I’m wrong I will gladly accept that, but I don’t think I am.
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well you didn't poop in my cherrios, but the machine shop just did. my blocks junk. cracked from the main bearing to the #4 cam bearing and all the way up to the lifter galley. so i guess I am going to reevaluate my combo and see what block I can find to fit my balanced rotating assembly...:BangHead:
 
shittyslant6 said:
well you didn't poop in my cherrios, but the machine shop just did. my blocks junk. cracked from the main bearing to the #4 cam bearing and all the way up to the lifter galley. so i guess I am going to reevaluate my combo and see what block I can find to fit my balanced rotating assembly...:BangHead:
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Dang that sucks. I just gave away my only 318 or I’d offer to help.
 
shittyslant6 said:
well you didn't poop in my cherrios, but the machine shop just did. my blocks junk. cracked from the main bearing to the #4 cam bearing and all the way up to the lifter galley. so i guess I am going to reevaluate my combo and see what block I can find to fit my balanced rotating assembly...:BangHead:
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that sucks, what a kick in the stones.
 
shittyslant6 said:
well you didn't poop in my cherrios, but the machine shop just did. my blocks junk. cracked from the main bearing to the #4 cam bearing and all the way up to the lifter galley. so i guess I am going to reevaluate my combo and see what block I can find to fit my balanced rotating assembly...:BangHead:
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Well that bites. Start a wanted ad and see if someone local has one for you. Facebook Marketplace is another good place to look. There's always someone looking to clean out their garage.
 
Marketplace for sure.. can still get a whole motor for 100-200..
 
Just as a for instance. I see a complete 360 with transmission for $75.. There's a Lean Burn with 302 heads for $75. Look around for deals and all within an hour drive. They are out there.
 
Bummer... I'd be leaning towards a 5.2/5.9 Magnum swap in that case though. 5.9L Magnum with a reground cam, 4-bbl intake+carb and headers would make well over 300 HP and it is very possible to find high-mileage Magnums that don't require a rebuild. Stock 5.9L flex plate has external balance weights so you can keep your current torque converter. Or stick with 318/5.2L displacement which are cheaper and more plentiful and internally balanced.

FWIW I put a 5.9L Magnum short block with LA top end in place of a 360 LA in my Duster and it was very straightforward, hardly had to change anything.
 
Just so you know;
a 4.10/33 combo maths to 65=2715 rpm .
a 3.55/28 combo maths to 65= 2770
a 3.23/25.5 combo maths to 65=2770
The point is that your 4.10s, by themselves, do NOT point to performance gears.


you can solve all your problems with Torque Multiplication, starting with a stout low-rpm engine and a good convertor.

I have an 84 D100-2wd with a low-compression 318 long-block from a 73 Dart; with nothing but a small-port 4bbl, headers, and a 2800/904. She's running 28s with 3.23s today. After I fixed the wheel-hop, she lays pretty good rubber. That 2800 was a game-changer.
 
Just keep in mind, even with the magnum cores, they are getting a lot of age on them now, too. You used to could find low mileage examples easily that needed minimal to no machine work. Now it's not so easy anymore.
 
Icetech said:
Naw.. not with how i build/tune.. my motto is "Mediocrity at any cost!"
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Oldmanmopar said:
Built many trucks and all had 410's. My choice in the same truck was a completely stock 69 340 with the AVS it came with. It pulled like a freight train.

I had a 73 360 HP in one and I did not like it. The only other choice would be a P pump 5.9 or 2004-2007 5.9 Common rail. I did that too the problem was the cost. I also did a Dyers blower on a 340, The common rail out performed it. You ask for an economic advice Look for a 10.5 340 use iron heads and dual plain intake.

" Or keep your 318 and install early 340 large valve top end and cam". This would be the best bang for the buck. Now this is my opinion on what worked for me using what I had, I am sure there are late magnums out there that would work just fine with fuel injection for today's fuel.
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I agree, if you can find one. I dropped a 69' and then a 70' stock 340 in my 72' B300 Maxi van, years ago and what a big difference there was from the stock 318. Could not feel the pop-up camper I pulled with it. Even raced a 350 Chevy truck while pulling the camper and beat him. We started at 45, passed him at 60 and I slowed down at 100. I always wondered if he ever told the story.
 
My two cents are have a local outfit grind you a cam for your motor with your intended use! They can dial you in depending on manifolds vs, headers, rear differential gears. Similar price to shelf cam. also 66 273 closed combustion heads #920’s get you low end torque… good luck!!
 
superdart said:
This entire discussion is for a 318 that is in my '77 M880 Power Wagon. I'll skip the details of how we got where we are now...but it's original and losing core plugs, 3 in the block so far. The latest is under the starter. Not hard to replace....but only a matter of time before I blow one out on the road. So I need to pull the engine to get to everything, so I might as well go ahead and do the rebuild I had originally planned for a few years down the road. Engine is a 318, all stock internals the valves guides are wasted but we dropped in new valve seals so it doesn't smoke much at all. I added a 625 AFB carb and Wieand Stealth intake. Headers are Summit block Huggers, exhaust is 2.5 pipes to a single 3" Walker Super Duty muffler. I have a Pertronix vacuum distributor and MSD Streetfire box to install, but the factory ignition is working fine for now. Don't ask about my haphazard methodology. I was just trying to get it driving so I could figure what else it needed after sitting 30 years.

Drivetrain is a 727, 203 full time transfer case, Dana 60 rear/Dana 44 front with 4.10s and 33" All terrains.

Here is the dilemma..what to build? It's just a toy. I have a car trailer but doubt I would ever pull more than 8000 lbs, and only local in flat-ish north Texas. No mountains, no long distance highway stuff, and not very often. After driving it as-is, it gets down the road pretty well (you know, 4.10s), I just want to give it a bit more for pulling to make it a well rounded all purpose vehicle.

Here's where the questions come in:

My Dart has a set of decently built 596 heads, adjustable valvetrain, etc on its 360. But, I scored a set of RPM heads from the Summit discount shelf. When I swap those heads on, the 596s will be available for a 318 build. My thought process is a set of -6 cc KB399s, the 596 heads, and pick a good torque biased cam suitable for the truck application. Or I could also just get the KB167 pistons to tighten up the existing chamber volume, but then I'm still running small 318 valves, if that even makes a difference for my application.

Thoughts? I'm open for discussion.....but "360" and/or "stroker" are not part of it. Not planning a repower and stroker will be utterly wasted in this application, and then we're into stall converters and stuff I'm trying to not get involved in. I have other vehicles that need that funding.View attachment 1716326729
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This past summer my brother and I finished a similar build in his Trailduster. Similar meaning the primary focus was torque, towing the 3000lb trailer, and probably never seeing over 4500rpm. We built a 360 using the Lunati VooDoo 10200701. For a 318 I'd use the next step smaller (which is currently available and $111 directly from Lunati) 10200700 253/258 208/213 .454/.454 lift.
The Trailduster idles at 19" of vacuum, 16" with the a/c on, doesn't ping, and burns the cheap 87 octane. He has commented to me several times about how good this truck runs compared to all of his past 4x4's
I agree with previous posters, spend the time dialing in the advance curve. We cheated and used a progression ignition distributor, but it still took several hours of him driving and me tuning to get the timing curve perfect. Also, don't be afraid to use the 360 heads.
 
I’m a big fan of the progressive ignition distributor..they still have issues fitting some big block mopars… it makes it so easy to dial in the curve…
 
It’s a company that builds a Bluetooth powered advance! Along with many many other features.. you set up a curve, it graphs it for you and you can watch it and adjust on the fly! It has proved to be quite reliable, but can also be used as tool for dialing in getting your numbers , and transfer that to your original distributor.

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