Correct, i'm running 11.25cr with j heads, 93 works fine with 30 total, seemed to run the same with 110 leaded at 35 total. i have 205 cranking psi, if i'm going to race it then i'll add race gas and bump the timing. also a lot of other things go into your octane requirements like quench, stall converter, car weight, fresh air system, fuel temp, etc..