I just bought an '88 350 TBI with a 700R4, that came off from a Suburban. The problem is that I do not have the ECM. I'm planning to buy a used one, but I do not know how to buy the correct ECM. I know that the original unit had a SERVICE # 1227747, but also it has other numbers. Wich are the important ones???, Would any ECM from a 305, 350 work???
Any help I will really aprecciate
Thanks

 

any TBI ECM will work but the truck ones are the most common and well known. If you get a 305 one from a car you can get a chip from a 350 Caprice (the big cop car chevy)

 

make sure it is a TBI automatic ECM and not a stick(if your car is auto), also, make sure it is from a 1992 or older! The 1993-1995 vehicles had a 4L60E