I'm just a tick over 10.8 with my 493 Indy head engine. I cant hear any detonation with the pump 93 here in NE Ohio and it runs very well. I haven't checked my cranking compression with my new cam but it seems to run good on pump 93 beer I limit my total advance to 34degrees mechanical with no vacuum advance.
Gus beer

64 Plymouth Savoy
493 Indy EZ's by Nick at Compu-Flow
5-Speed Richmond faceplate Liberty box
Dana 60