[aldersonjames20]

So it sounds like there is no hard and fast rule then. As I said, I am somewhere between the 10.5 and 10.8 numbers I have been told. Its an all aluminum Dart block 351W bored and stroked to 427 with aluminum (AFR 205) heads and I run 93 octane only. The 93 is at almost every station around here and alot have 100 race fuel, but I didn't think I needed it... so do I? What if I plan on running a dyno? If I run a road race I would put race fuel in for sure, as thats what its for... but just cruising with the occasional squirt of the loud pedal???

James