[Super73]

To me that seems low for an optimized set up. For example, you can run 91 octane in a motor with 8.8-8.9 dynamic compression (compression based on where the intake valve closes). Here are some examples of what I'm talking about:

11-1cr 285* duration at .006 108 intake center = 8.35 dcr
12-1cr 285* duration at .006 108 intake center = 9.09 dcr
13-1cr 285* duration at .006 108 intake center = 9.87 dcr


11-1cr 308* duration at .006 108 intake center = 7.45 dcr
12-1cr 308* duration at .006 108 intake center = 8.10 dcr
13-1cr 308* duration at .006 108 intake center = 8.80 dcr


IMO, choosing close to max DCR you can run based on fuel is a good starting point. Then from there, figure out what intake valve timing you need for your planed RPM usage. Once that is established, work it backwards and figure out what SCR you need to have X DCR. Then mill heads, buy appropriate gaskets and pistons to position your SCR where it needs to be.