Can cranking compression give any indicator as to what you can get away with? My motor is a 10:1 W2 headed 416. The pistons have a nice smooth dish and no quench. Solid roller, 270ish @.050 off the top of my head, last cranking compression was 165. I just got it running again after a fresh valve job and replacing an incredibly worn timing chain so I need to check it again. It makes about 575-600HP now and has no trouble on 91 octane with 40* of timing WOT.

I had a 340 that was 10:1, quench motor, 243@.050 hydraulic flat tappet with rhoads clickety clack lifters. It cranked like 210psi and ran on 93 octane.

I would like to bump the compression up on the 416 on the next refresh but I do not have the budget or desire to run race gas since It is a street car. I do have E70 available in town and the fuel system to support it but I get mixed reviews about ethanol and limited use street cars(I don't drive it near as much as would like to).