Okay guys I have a 1999 silverado 1500 rcsb that has a 4.3 v6 and 2wd.

I just purchased a low mileage lq4 and 2wd 80e combo from a 2002 2500. The dropout is complete with harness, ecu, all accessories etc.

what is my easiest route to this swap? Keep my stock ecu and reflash? Just plug in the 6.0 eeu, will it work? Should I swap the trans harness with the new one or do I need to get the conversion harness?

what cross member do I need? There seems to be a few different ones. Drive shaft?

I've searched a lot, but some of the info is indecisive, or touches on the subject, but doesn't have the answers I need.

any help is great appreciated. Thanks.






edited for spelling

 

you're going to have to use the harnesses that came with the engine and trans. the 4.3 and 4l60e harness are going to be different. Same with the ECU.

What I do remember is from back in the day when these trucks first came on to the scene. the biggest issue people had was with the body control module on the cab. people were having to get it reflashed at the dealer. but that's about all I remember. probably have to swap the dash as well. that's pretty easy though.

as for crossmembers, should just be for the transmission. for that, I'd do a search for 4l60e to 4l80e swap. that should get you what you want for that. the engine should just be mounts.

might have to replace the radiator with one for a v8. I think the V6 ones are smaller.