What all would be required to swap a V8 from a 96-98 Silverado into my 97 Cheyenne full size truck with the 4.3 vortec V6? Would I need the ECM and harness from the V8? Will the V8 bolt up to the stock 4.3 mounts?I've been unable to find any information on this. All the information I could get on this would be greatly appreciated.

 

All I can tell you is that it will be a nightmare! You have a 350 in your silverado right? Everything is different on the Vortec engine as far as electrical, ECM, and the fuel system. not to mention the frane mounts....you might be able to pull it off, but it will require a lot of parts and customization...
good luck!

 

i dont think it would be as hard as that guy said. the 4.3 is basically a 350 minus two cylinders. i believe the tranny mounts up. but idk how the motor mounts will line up bc the 4.3 has to be shorter bc its missing a piston on each side. if you get the full engine harness and ecm it should go right in. and if your state doesnt have computerized emission testing for inspection, why dont you just carb it, then you only need like 5 wires to make it run. its def a possibility bc i doubt gm made different sub frames for different engines. they are lazy and make as much as possible the same. im willing to bet it will line up with minor head ache. try it and let us know. be sure to take lots of pics. and it bet it would make it a lot easier if you took the hood, fenders and radiator support off.

 

I'm not an expert but I dont think its as simple as just Carbing the motor, the aluminum 5.7 Vortec isn't exactly the same as the the iron 350. Also I DO agree that in the end it won't really be worth it and 97 Chevy should look for a cheap Silverado with the right engine to begin with.

 

i must have missed the part where he said his donner engine was from a vette-'cause i'm pretty sure the engines in the '96-'98 trucks were iron. the wiring harness will swap out between the 2 trucks, and u won't need to custom fabricate anything (u have 2 identicaltrucksto transfer the parts back and forth as u need).but i do agree with the other guys, it will be quite labour intensive, and unless your truck is exceptionally clean, it's not worth it (take it from my past experience in doing things like this)

 

i got 1991 the cheyenne w/t, and have done everything and more to convert it over to a silverado, and the engine is on my to-do list in a year hopefully when i have some funds saved

from what i know:
It is a fairly easy swap, extremely easy when compared to swaping engines on imports and stuff. the 350 has the same frame bolt locations as the 4.3 (252), and connects to the transmission and everything without having to buy new parts. i think the only thing u have to pull besides the ECU is the new intake manifold. also, if your cheyenne is older 252 like mine, and you're going to a 96+ 350, you're switching from the older chevy throttle body 252 to a Vortex 350, so I dont know if that requires any more modifications. i would suggest trying to find a 350 in the same year your cheyenne is to minimize problems.

also, another solution which ive always considered for my lifted 2x4 is to just do a body swap. find an old K1500 with a good frame and the 350 you're looking for, and swap the bodies, and sell the 'new' cheyenne and keep the now 4x4 cheyenne. there are only 6 bolts holding the entire body and cab setup on the frame for the 88-98 generations, so its not too hard

 

yeah that makes an easy swap!!! Lets change the engine AND the entire body!!!

 

hello, I want to know the difference between the harnees of a cheyenne v8 1996 and the 1998, all this because I want to make my 1996 full injection, does somebody knows what its the difference just to be sure what harnees I really need to change cause they are like fivem but if they are the same I do not have to change anything

 

too much work to justify doing it

 

I have a 04 Silverado with a tired 4.3 Vortec. My buddy just had his 09 Siverado with a 5.7 vortec totaled, the whole *** end was ripped off but trans and forward mechanically are 100% bank left it to him to salvage and i could get everything i would need next to nothin. Will the engine and trans easily swap? Or just Engine? What you'all think?