I have a ‘92 1500 that has the 4.3 tbi motor. I have an ‘89 350 to swap into it. I was wondering if anyone could tell me what i need to change on the electrical side(PROM, sensors, etc)? And fuel delivery wise? Any feedback is appreciated!!

 

Might need ECM programmed. Need a shorter fan shroud. I think but don't know if the exhaust pipes will hook up. At least it's all OBD I.

 

I did the 4.3 to 5.7 swap. You will need to remove the 4.3L motor mounts, which is a pain. My 5.7L had ebay headers, but they mounted to the stock exhaust just fine. As for sensors the TBI injector wiring will need lengthened a few inches, as will the knock sensor wire. Everything else should bolt up. My 94 4.3L had two knock sensors, but I only used one on the 5.7L. You will need a new PROM as well. If the 5.7L is stock, you shouldn't need a custom PROM.

 

Any tips on where to get a PROM chip from? Everything is stock, except headers and i bought 5.7 injectors to replace the 4.3 injectors. Ive read there interchangeable parts. And the motor mounts, i have the portion that is bolted the the block, but the frame mounts I have to change, right?

 

I bought a stock PROM chip off an eBay vendor, but ended up neeya custom one. The V6 mounts that are bolted to the frame will have to go. Take your time and go slow as they are hard to reach. I had issues getting the fuel line connected to my TBI unit, but the shop that finished up everything got them connected. I looked at my friends C1500 with 350 and his had braided lines if I recall, and mine were steel tube. Also the starter wire gave me an issue, but the hole basically needed slightly enlarged.


I tried to document everything as best I could here:

https://chevroletforum.com/forum/198...00-4-3l-95882/

 

eBay has used ones for about $40 bucks. Make sure you get the correct one for your engine/transmission.

 

Could I get this and not have to do anything else but install it?

 

I think you can. A local shop rebuilt my transmission and actually got my engine running. They also figured out I needed a custom programmed PROM, so I don't want to unintentionally steer you wrong.

I bought the stock one that ended up not working with my cam combination through this ebay vendor. They took the time to verify my engine and trans combo before sending me the chip.
https://www.ebay.com/itm/Prom-Chip-B...72.m2749.l2649



Someone made a short and concise video how to replace it as well.

 

Would this work for the swap?

This is one of the last things i need and seemingly very crucial to be exact, so I would really appreciate an exact answer and/or other product!

1992 Chevy 1500, with a stock 4.3 and a 1989 350 engine replacing the 4.3