I have a 2005 chevy silverado 1500 with a 4.3 and want to swap to a V8. i also have a 2002 chevy suburban with a 5.3 that i can pull the motor out of but i don’t know if the wire harness will work, or if i need any thing extra to make it work
Please give write back if you know the answer thank you

 

Please do some searching on this forum. There is a specific 4.3 to V8 thread that has tons of information.

In short, yes that engine will fit. But you need the lots of other stuff to make it all function like wiring etc etc.

 

especially going from an 02 into an 05 - there's a few key differences in electronics

 

Different powertrain control module and the tune operating inside it is vastly different.

Rick

 

The harness will not work you need a 2003+ engine harness. You'll need to find a 2003+ harness, PCM, TAC module, accelerator pedal and drive by wire throttle body off a 2003+ truck/suv. To keep the cable throttle (easier but harder to find) you'll need an engine harness and PCM from a 2003+ Gen3 Chevrolet Express van or a GMC Savana van. The vans kept the cable throttle while the trucks/suv's went to a drive by wire system.