On my sticker there is no difference for manual trans with or without A/C. The only difference for auto trans cars is a slight increase in idle speed. I also looked up the the specs for the amount of vacum and mechinical advance for 1978 nova and camaro. Both cars use the same part number and advance curves for auto OR manual trans. In other words you could run 10 degrees of of advance to start and if it doesn't ping it would be no difference in total advance from an automatic trans car.(a very tame curve IMHO)
I was misreading your post, the numbers are a little confusing in sentence format versus table format. Yeah, that's what my numbers for auto and auto/AC are too. The change from year to year, but seem to be the same for all models with the same engine during a model year.
Working on timing today with my new timing light, after I pick up a warranty replacement battery. The timing marks on the L6 are a bit different. I'm working off the assumption that the widest V is the zero at the bottom with -4 TDC being the tip above and 4 is the tip below. So I'm adjusting for the bottom of the next cutout for 6 degrees. I should clean it up more to see if I can find some numbers.
