So I'm trying to track down the proper ECM and PROM for my 305-350 swap. And i had determined that the ECM that came with my 89 Iroc 305 TPI would work, and I would just need a prom. But today I pulled it down and this is what I found. Its a reman ECM, and the numbers don't seem to match up with anything on this list. http://www.3rdgenformula.com/89/promcodes.htm

So i was wondering if any of you experts out there could help me determine what ECM this is. Your help is greatly appreciated!

 

I believe it is the replacement for a 1227165 which is what was originally in there, but can anyone verify this for sure?

 

Call your local GM dealer and talk to the parts department and give them that number on your ECM. GM likes to change part numbers for no good reason a lot and when they upgrade a part.

Was this ECM running your 305 TPI with no codes or problems? If not, it will work with a 350 TPI Prom.

86-89 305 TPIs used the 1227165 ECM in F-bodies.
87-89 350 TPIs used the 1227165 ECM in F-bodies.

 

http://www.trademotion.com/partlocat...&siteid=213800

If you select chevy then on the next screen click on the P/N it will give you more info about what it fits.

 

I called 3 different GM dealers and none of them seemed to have any record of this number existing. I used that website and it told me no more than I already knew, that it would work. Is the 1227165 the ONLY ECM used for 86-89 TPIs though?

 

The only one I've ever seen or heard of being in a 86-89 TPI F-body is the 1227165. The Vette ECM is the only other ECM that might work with your engine but it looks different. The ECM doesn't do that much its the Prom that does most of everything.

Is your car with the 305 TPI running good with the ECM you show in the pics?

If so, I believe you are making a big deal out of nothing.

 

The 86-89 vette also used the 165 ECM, the 88999194 is supposed to be the "improved" replacement for the 165, drop in a 350 prom in it and you should be fine.

 

As I had stated to you in a previous thread I bought the car blown up and knew nothing about the running condition of it.

Thanks convas, thats exactly what I was looking for. I knew someone would know this.