[guru of dirt]

I have a 1994 Chevrolet Cheyenne 2500 4x4 with manual trans with low & OD, was a northern truck and well maintained just salt has ate frame up. Found a 1998 Chevrolet Silverado 1500 4x4 with 4.3 5 speed manual motor threw a rod.

Can I swap the 94 5.7 into the 98 4.3 or do I have to keep the 94 manual trans with the 5.7?

radiator swap and wiring harness from 94 to 98 what else will I need to do. Now this is a hunting/farm truck deal so not a Daily.
PICS FOR REFERENCE LOL

94 is brown
98 is burgundy

 

[1988K1500since1999]

Anything can be done, but man, you're swapping an OBD1 engine and system into a OBD2 truck. You will have to completely gut, rewire everything, and swap the dashes. Even if you could fit a new style intake on the older 350, I'm not sure how your wiring would mate up to any needed sensors. Not to mention, you computer is programmed for the V6 engine. No way would I attempt this! I swapped the 305 to 350 in my '88, and that was a plug and play deal. I had to install another chip in my computer, but the 350 sensors all plugged into the 305 harness for the 1988. My recommendation? Get another donor OBD1 truck (1988-1994, 1995 had different interior) and start from there.

 

[guru of dirt]

Anything can be done, but man, you're swapping an OBD1 engine and system into a OBD2 truck. You will have to completely gut, rewire everything, and swap the dashes. Even if you could fit a new style intake on the older 350, I'm not sure how your wiring would mate up to any needed sensors. Not to mention, you computer is programmed for the V6 engine. No way would I attempt this! I swapped the 305 to 350 in my '88, and that was a plug and play deal. I had to install another chip in my computer, but the 350 sensors all plugged into the 305 harness for the 1988. My recommendation? Get another donor OBD1 truck (1988-1994, 1995 had different interior) and start from there.

 

[guru of dirt]

Hard to find a manual truck anymore all
Autos lol

 

[1988K1500since1999]

Hard to find a manual truck anymore all
Autos lol

Much easier to convert an older auto truck to manual versus the complete computer system swap you're thinking about doing. But that's just my opinion. You're about to have to strip each vehicle down completely to the sheet metal inside and out and basically build your way back up. Even though the bodies are similar, the frames and cab chassis do have some differences that you will need to address along the way. In the end, your interior from the older truck will have to go in the newer truck in order for all the wiring/components to work. Once you swap your dash, the door panels won't line up. So you'll have to make your doors like 1994, but the inside door handles are different. The door shells may work, but you may have to notch them in order to fit the older window regulators into the newer doors. At least that's what I had to do when I replaced my '88 doors with '95 doors. It's a major undertaking. And since you'll have a 1998 VIN with 1994 components, you may run into issues when getting it inspected because it will not have required emissions on it versus the 1998 truck. I'd recommend finding an older OBD1 (1988-1994) truck to fix up instead. Much easier to swap stuff between those years.

 

[guru of dirt]

Maybe I can find a 4.3 bottom end then as rod ran out bottom at 272k lol

 

[RayVoy]

The rod may have damaged the bore before going through the pan.

You have what sounds like an easy swap until you toss in the problems with going from OBD to OBD2.

I think if it was me, I'd consider converting the '98 to OBD.
Take everything under the hood and the dash out of the '94 and move all of it to the '98.

I've never done it, so it may be a bigger job than I'm picturing; but look it over, see how close things line up

 

[Cowboytrukr]

Here’s the thing. The ‘98 transmission will not suffer the extra power of the 5.7. You will grenade It. Been there done that with my ‘95. Went from a 4.3 to a 5.7. Great swap, but it blew up the NV3500 that she was born with.

You could swap the entire computer system and harness over from the ‘94, but that’s a crap load of work. The ‘94 block is a flat tappet engine with the intake side of the heads drilled differently than the ‘98 5.7. The ‘94 heads are probably the worst flowing heads GM ever made. You might not be able to get a ‘96-98 intake to bolt up to your ‘94.

I would take that NV4500 that’s on your ‘94 any day of the week. Those things are practically bullet proof. Now to figure out the least costly way to get the 5.7 running in the ‘98 chassis.

@PlaywithTBI Peter. Any ideas here?

 

[guru of dirt]

Here’s the thing. The ‘98 transmission will not suffer the extra power of the 5.7. You will grenade It. Been there done that with my ‘95. Went from a 4.3 to a 5.7. Great swap, but it blew up the NV3500 that she was born with.

You could swap the entire computer system and harness over from the ‘94, but that’s a crap load of work. The ‘94 block is a flat tappet engine with the intake side of the heads drilled differently than the ‘98 5.7. The ‘94 heads are probably the worst flowing heads GM ever made. You might not be able to get a ‘96-98 intake to bolt up to your ‘94.

I would take that NV4500 that’s on your ‘94 any day of the week. Those things are practically bullet proof. Now to figure out the least costly way to get the 5.7 running in the ‘98 chassis.

@PlaywithTBI Peter. Any ideas here?

Thanks man as long as I can trade everything I need from my 94 to the 98 I’m good as the 94 frame is BAD RUSTY. I’m good with swapping engine and tranny from 94 to the 98 as well as harness and computer. This is. Just a old farm/hunting truck if the drivetrain wasn’t soo good in 94 it was well
Taken care of just sally ate it up in Pa. Where guy bought it brand new he moved back down here to live with his daughter and Va. denied it in inspection to be on road. So between both trucks now I have $1100 in them both. Just use it to haul wood and hunt from on 3 separate farms in a 5 mile radius from farm I live on. Im gonna take transfer case and rear end from it as well and anything else I need now or later and haul rest to scrap yard. Thanks for your response as well as tagging someone else with experience on this. Just trying to figure out what I need to do to get game plan going after I pull
Both engines for the swap from the 94 to the 98.

 

[1988K1500since1999]

The rod may have damaged the bore before going through the pan.

You have what sounds like an easy swap until you toss in the problems with going from OBD to OBD2.

I think if it was me, I'd consider converting the '98 to OBD.
Take everything under the hood and the dash out of the '94 and move all of it to the '98.

I've never done it, so it may be a bigger job than I'm picturing; but look it over, see how close things line up

Thanks man as long as I can trade everything I need from my 94 to the 98 I’m good as the 94 frame is BAD RUSTY. I’m good with swapping engine and tranny from 94 to the 98 as well as harness and computer. This is. Just a old farm/hunting truck if the drivetrain wasn’t soo good in 94 it was well
Taken care of just sally ate it up in Pa. Where guy bought it brand new he moved back down here to live with his daughter and Va. denied it in inspection to be on road. So between both trucks now I have $1100 in them both. Just use it to haul wood and hunt from on 3 separate farms in a 5 mile radius from farm I live on. Im gonna take transfer case and rear end from it as well and anything else I need now or later and haul rest to scrap yard. Thanks for your response as well as tagging someone else with experience on this. Just trying to figure out what I need to do to get game plan going after I pull
Both engines for the swap from the 94 to the 98.

Good luck. Hope it goes well for you!

 

[guru of dirt]

Good luck. Hope it goes well for you!

Thanks

 

[PlaywithTBI]

@PlaywithTBI Peter. Any ideas here?

Not really, as Ray said the dashes are different jn that the 98's PCM feeds them while the 94 is fed directly from the gauges.

As Greg said the intake manifolds won't swap so you'll need to keep it TBI. A Vortec 4.3 will perform pretty close to a TBI 5.7 and yes, the TBI cam and heads are pathetic!

If it were me, I'd try to find a Vortec engine for the 98 and scrap the 94 (maybe keep the better trans), it's outlived its usefulness - just saying

 

[guru of dirt]

Not really, as Ray said the dashes are different jn that the 98's PCM feeds them while the 94 is fed directly from the gauges.

As Greg said the intake manifolds won't swap so you'll need to keep it TBI. A Vortec 4.3 will perform pretty close to a TBI 5.7 and yes, the TBI cam and heads are pathetic!

If it were me, I'd try to find a Vortec engine for the 98 and scrap the 94 (maybe keep the better trans), it's outlived its usefulness - just saying

Ok so if I find a 98 vortec v8 will be much simpler to swap out the 98 v6 truck as this v6 expired at 272k and heard pretty expensive to find a good vortec v6. Thx

 

[1988K1500since1999]

Ok so if I find a 98 vortec v8 will be much simpler to swap out the 98 v6 truck as this v6 expired at 272k and heard pretty expensive to find a good vortec v6. Thx

Unless you want a V8, just get a rebuilt or crate V6 and drop it in, or visit a junkyard and get a running engine. By the time you screw around with swapping all the crap around, you'll probably have the expense of a replacement engine in the project. Just my $0.02. I just think this project is going to get difficult, frustrating, and expensive. Sounds like you just want a simple truck that runs. I'd use the 'KISS' method. Keep It Simple Stupid. I'm not calling you stupid! It's just how the saying goes, but you get the point. Don't complicate it if it doesnt need to be complicated. That's my philosophy. Good luck to you.

 

[guru of dirt]

Ok guy said put set of vortec heads and Intake on the 5.7 tbi engine and will be way better than trying to change and rewire the whole harness, computer.

 

[Cowboytrukr]

That is a viable alternative. You will still need a new computer chip to get the computer to do its job.