Hi everyone,
Im swapping in an 89 l98 from a trans am into my 86 iroc. Right now stock I have a 305 tpi auto. The 89 engine I got is complete with wiring harness and computer. My question is what else ( if anything ) will I need to swap this engine in correctly with no complications. I will be using my existing tranny. I believe its a straight swap but am not sure as they did not make the 350 tpi available for our cars until 87. I appreciate any help I can get, I`m swapping in the spring and just want to get any parts I need beforehand. I did try searching and found some help but just want to clarify anything I need. Thanks again

Welcome aboard thirdgen.org.

If the harness includes all the sensors etc., including the knock sensor module, you won't need anything else.

The accessories changed from what they were in '86 in '88. You'd be better off putting your '86 accessories on the '89 engine.

Thanks, yeah Im planning on swapping my current accessories over to the 89

can I use my 86 wiring harness on the 89 engine to keep it simple ?

another question i have, is the ESC of the 89 engine embedded on the prom or is it a seperate module ? i've read somewhere that 85-88 's had an ESC module but after that not sure..

it is a seperate module, you should be ok keeping the same esc module

even though mines for a 305 ?

There have been conflicting reports about the EST, so I'd say to be safe use the 350 stuff.

The differences between the '86 & '89 are probably enough reason to keep the TPI hardware and harnessing together.

alright so I'll use the 86 accessories on with the 89 harness. Will there be a problem with fitting though because the 86 accessories are v-belt and wiring harness is made for serpentine setup? because the alternator and ac compressor switched sides between the two

Use all the '86 stuff - accessories, TPI, harnessing. Use an '87-'88 350 PROM/tune.

Sounds good, I have the 89 prom though so it wont have the cold start in the prom, I guess its just fine I'll just plug up the cold start sensor in the manifold and the computer wont recognize it, and ill leave the cold start sensor wire unconnected from the harness.