1995 c1500 4.3 to 5.7 questions

[Grant Henderson]

I have a 1995 c1500 4.3 manual rcsb, I want to drop a 350 in it.

I have a 1995 k1500 5.7 auto ecsb donor truck.


What it everything I need to make this work?

My biggest concern is with the computer, everything I have read up to this point makes me believe I will need a new one. My understanding is I need a 1995 c1500 5.7 manual computer(are there any other factors that go into computer selection?). From that point on its just plug and play/nuts and bolts? Sorry if this is a stupid question but i'm just trying to cover my ass before I rip my trucks apart.

 

[Schurkey]

Will the six-popper clutch and transmission last behind a 5.7? If that's the transmission GM used on the 5.7L, and you don't want to upgrade to the heavier-duty trans, I'm thinking you have almost all the parts you need except the computer. I can't help you with that. MAYBE it's the same computer with a different "chip". I don't know.

Bigger radiator, shroud, and fan from the donor, engine accessory mounts and the accessories from the donor (which may be the same as what you have, in which case use whatever is in better condition.) Make sure the exhaust manifolds aren't cracked, plane them if they're warped--or replace with headers.

Does the '95 still have a pellet-style catalyst? You'd want to upgrade to a monolithic (Honeycomb) catalyst. When it was me, I made sure that all the pipes after the catalyst were stainless steel, and at least as large as OEM or bigger.

If you have JB3 brakes, the extended-cab should have JB5. At some point GM dropped the JB3 and everything got JB5 or better. My '88 K1500 had JB3 until I upgraded.

The 5.7L will weigh more than the six-popper. You may need stiffer front springs, potentially a GOOD front-end alignment including thrust angle, and almost certainly HEADLIGHT ALIGNMENT. The K1500 would be torsion-bar, but the 2WD is coil springs...right?

Make sure the fuel delivery system is able to support the additional engine power (fuel pump in good condition) and assure that the radiator you use is clean inside, with air fins that aren't corroded away from the water tubes. Fresh coolant and PS hoses, probably fresh serpentine belt and tensioner pulley.

Consider whether you want to re-seal the engine while it's out. Likely need a repair sleeve on the damper at any rate. Would be worth checking the timing chain.

Replace the clutch parts while it's out? Don't forget to shove a pilot bushing in the 5.7L crankshaft.

You'd want fresh rubber engine mount cushions; but the aftermarket ones are JUNK. If GM still sells them, and GM isn't just selling aftermarket crap in a Genuine GM box, that's the way to go.

 

[Grant Henderson]

Thanks for the info

Before I decided I wanted to 350 swap I put a new clutch in it(nv3500 im sure is capable of stock tbi 350 power), i'm not sure it hold up but I think I will just roll with it for now hahahah.

As far as brakes go dont really wanna rip anything off the donor truck because I am currently rebuilding a lq4/4L80E to drop in, but I think I have it covered I did the gmt800 brake booster already and have a gmt800 10 bolt with disc brakes I'm currently putting in the truck. Not really worried about the springs atm, going for the lowered truck (axle flip and notched frame).

I guess its kind of a rare computer spec I should have a fun time looking for one

At any rate thanks for the info

 

[Erik the Awful]

As far as I can find, the NV3500s are all the same, even if it's from an S-10 (NV1500s are a different story). It'll hold up to a beefy 350 so long as you don't launch it on sticky tires.

The stock V8 radiator in my '89 is pretty dinky; I can't imaging the V6 radiator is smaller. I'd upgrade to the K1500 radiator if it's larger and in good condition. Then upgrade the K1500 radiator when you stick the LQ4 in it.

 

[PlayingWithTBI]

My biggest concern is with the computer, everything I have read up to this point makes me believe I will need a new one

You can get a chip for the 5.7 or get the whole PCM. You'll want one with the same gear ratio too or the PCM will think you're running at a different speed than your speedometer and cruise control do. With a manual trans it's not a big deal.