1st gen v8 swap

firstgenowner

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hello everyone, i have a 1992 d150 with a 3.9 v6 and a np2500 5 speed. i need to figure out what transmission to use. im also debating on whether i should build a 390 stroker out of my 318 LA or put a turbo onto it. it would be great if some one could help me out with the turbo route on what needs to be done,

thanks in advance.
 

reek

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as a generic statement, you'd benefit from upgrading the headers - back, check the specs of the motors internals, possible check the ring gaps, upgrade fuel system, and engine ECU upgrade.

Personally I am a fan of displacement with better breathing rather than pressurizing. a 390 stroker would be bad ass. I almost went that route but kept it simple and built up a 5.9 Magnum with 4 barrel dual plane intake with TBI, hotter cam and long tubes. probably sitting near 300 hp at crank. never dyno'd to be sure though.
 

firstgenowner

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what are the limits of the stock internals. being that the motor in question is from an rv, im assuming that it has a forged crank and ive heard that the cast pistons have lived to 800hp. for the stroker route im looking at about 2700 bucks in parts, not to metion what the machine shop would charge for doing head work and machining the block. what kind of power would i be looking at with 10.5 compression, 390 cid, edelbrock rpm air gap, 1 5/8 primary headers, and factory heads with some bigger valves and some porting and polishing
 

reek

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what is your target HP at crank? your v6 is probably near 180 hp stock. 100 hp ideal with a turbo takes you to 280-300 hp.

Most strokers seem to claim 400 max. so I'd guess you could get mid 300's to 400. Depending on what year your 318 is, you could easily convert to a roller Cam set up and Magnum 5.2 heads. they breath better with bigger valves than LA heads and could save you some cash. the 5.9 and 5.2 magnums use the same heads/pushrods. throw in more aggressive cams, 4 bbl intake you could probably get into the low to mid 300's.

I went the lazy man's way. Bought a Parks Dept retired 2001 Ram truck with a 5.9 magnum with 90k miles for $1500. rebuilt the engine myself with a hotter cam, 4 bbl air gap intake, long tube headers. Parted out the rest of the truck and made more than half the cost back. I put the motor in my 73 D100. No dyno but I'm estimating low 300's hp since a stock magnum 5.9 runs 245hp. Just food for thought
 

firstgenowner

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dont really have a hp goal yet, i want to keep up with my dads 65 gt mustang (bone stock). how much hp do you think ill need with an od a833 4 speed and some 4.38 gears
 

reek

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dont really have a hp goal yet, i want to keep up with my dads 65 gt mustang (bone stock). how much hp do you think ill need with an od a833 4 speed and some 4.38 gears
ha! you'll need a smaller truck. JK. don't know what your dad's mustang has but in general 300 hp is a good place to be in my opinion. my 72 d100 (magnum 5.2) with a a500 and 3.23 probably is hovering just below that number and may 73 D100 (Magnum 5.9) with an a518 with 3.73 is probably just above that. both are short beds and neither are slouches.
 

drakon543

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id be more leaning at starting with the 360 not the 318. the 318 is a good engine but you have more room to stretch on a 360. bought a book from a guy from mopar a while ago and it mentioned how easy these engines are to stroke on the cheap if you wanted to. apparently with the right block and stroker kit and machining a 360 can be pushed to a 427. once you go down the road in hunt of more power you may find yourself wishing you had started with a 360 anyway. as far as going the route of boost you may also find yourself with a better benefit of starting out with a magnum out of a wrecked truck or something. your already going to be starting with an engine that can be computer tuned either factory ecm or standalone management system
 

u2slow

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The minimum LA I would start with for a power-savvy build is a roller 360 with the injected heads; but preferably a magnum.

318 is better to simply freshen up and be happy with the reduced fuel consumption over something larger.

Nv3500 or Dakota 6speed for a 5.2 magnum at the most, nv4500 beyond that.

JMHO.
 

firstgenowner

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the reason im going with a 318 is i can pick one up for 350 bucks and if its a 68-73 block i can turn it into a 418 stroker. if the stock bottom end can handle it, ill probably put a turbo onto it with a cam, some head work, intake, and a blow through carb. if anyone has any sugestions for the turbo route, please let me know.
 

reek

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the reason im going with a 318 is i can pick one up for 350 bucks and if its a 68-73 block i can turn it into a 418 stroker. if the stock bottom end can handle it, ill probably put a turbo onto it with a cam, some head work, intake, and a blow through carb. if anyone has any sugestions for the turbo route, please let me know.
not sure taking a 318 to a 418 is the best way to go from a cost and durability stand point. typical "home mechanic" stroker for a 318 is 390 and a 360 to 408. With the cost of machining a 318 and the stroker rotating assembly, unless you don't mind a short lived engine, I'd go find a magnum 360/5.9 block at a pick and pull for less than $250. around here a pick and pull complete engine goes for $221.99. you can run a more aggressive Cam with the roller magnum as well.

I don't think a 318 block will handle an over bore of 0.09 to get you to a 4.0 bore. with a stroker, you're essentially starting with a bare block anyway. So you might as well start with a better foundation.
 
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