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.
 
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.
 
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