Fuel grade and Compression ratio

10.54 - 1, zero deck (KB107030) piston a .030 in a 360 with Edel. heads and a Fel-Pro gasket @ .039 thick.
Runs on 93 best. Largest cam in it at the time was a Purple 292. No problems. Good quench, no pings.
RPM air-gap/750 Carter, hooker super comps.

The combo of compresion and cam can allow higher ratio's. Quenched engines can nudge it higher.