I think the rest of your combo might play a big factor, in the early 80-s we would drive from lower detroit to see friends and hit the brackets at avvila and bunker hill and with the 284/484 a 3k vert, 3:55 rear and some small diameter dirt track like slicks (put on there) would run pretty consistent 7.40s, most the time it was dead on 7.47.

The rest of the car was just a re ringed 360 and a ootb shift kit.

In my setup I forget the 60 ft times but its really what got the 7.40s to work because I never recall the car pulling very hard, just would hook and launch well.

Friends used to run the comp cam and it never seemed to do as well.