So, still new to all this, but I had some question for the beginner.

I have noticed that GM used 2 different ecm designs between 1987 and 1992

1987/90 - 24 and 32 pin connector
1991/92 - 32 and 32 pin connector

I think that's right:)
What were the differences between the 2? Are both OBD1?

Are the ALDL ports for them different?


lakedrifter