How about something like this? I'm running the ACDelco D1984A ICM.I will dig one up for you. I am scratching my head as to why you have so little timing at 4,800 rpm. I would try 32-34* at 2,800 rpm from 85+ kpa. Be mindful of the PE Spark Adder. I have also had combinations that wanted full timing advance as low as 2,000-2,400 rpm and yet others that wanted the timing advance slightly retarded at higher rpm. Finally, the ignition control module you are running can greatly alter the actual delivered timing advance.
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FYI, I used the spreadsheet developed by @84Elky posted on GearHead-EFI and Third Gen F-Body. Any suggestions?
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