1991 corvette

If you go to the GM EFI systems page in this forum you will see there is a subforum of hosted bin and definition files. Because there are alot of options here are the 3 main routs.

Here is the stock breakdown of the 7277 ecu from your C4
This is the S_AUJP thread with up to V4
Here is the V5 of the S_AUJP definitions - I use this for my 90 C4