GM has 3 different broadcast codes for the 91 350 TPI A/T which are ANJF,ANJA and AUJP. What are the differences between them if any? I have a ANJF and a AUJP that came out of 91 Z28s that had the same engine,tranny and rearend gearing. I'm wondering why GM has 3 different BC for the same setup? Thx.

 

GM sometimes released "running change" SW/Cals due to driveability issues, or sometimes to correct compliance issues with a package.
So that could be the difference in ANJF versus AUJP.

OR, it could be one was for VATS versus non-VATS for a particular model.....

 

I thought all 89-92 f-bodies came with VATS as standard equipment and VATS delete was not a option.
90-91 all 3 were used but in 92 only the AUJP was used.

Has anyone read all 3 of these to see what the difference were?

 

If in 1992 only AUJP was used, and before that, all 3, then that indicates a change due to some issues in the older cals (most likely either spark knock sensitivity or a driveability issue at some temperature or altitude......

 

Most likely they were updates for better drivability and or consumer complaints.
I know there are a couple different AUJP's also.
Best to go with the latest one you have available.

 

I read somewhere that a different prom was used in the cars with the 16" bigger tires and lower rear ends, and the prom was adjusted to calibrate speed.
Don't know for sure.