[DAVID GAGNARD]

Gotta agree with Bob on most all points....My 65 Fastback runs a 351-W,10.4 to 1 calculated compression,iron heads,93 octane,no problems,once I tried 89 octane and the valves rattled worse than a diesel....By retarding the timing it would quit pinging,but would run like crap....

Back in my dirt track days,we had to run "pump gas",93 octane max.,they checked the gas after the feature race. One race motor I built was 12 to 1 compression and we added our own "mixture" to it to get by,got caught one night and we were disqualified for illegal fuel.Next week out they checked us before,during,and after the heat race and feature.We ran pump 93 octane that night and it still ran pretty good so we kept running it. With open headers you cannot "hear" detonation,but after the second night out I new we had it. Pulled a compression test next day,then the head and found most of the lands on two piston gone...Since then we never ran more than 10.5 to 1 compression on pump gas and had no problems......

David