SB Mopar (360), hydraulic flat tappet cam (Hughes Engines HE3844AL cam, .535/.540 lift, 237/243 dur. @ .050", 286/290 adv. dur., 108 LSA.), 10.7:1 static CR, open chamber factory '596 head castings, heavily ported, chambers polished up and literally no quench volume to speak off (meaning it's absolutely dismal by all accounts, I have about 0.090" between piston top and chamber floor).

Previously was at 9.7, did a head re-surface to get to 10.7, my cranking compression went from 165 to 185-190 psi.

I run 91 octane pump-gas now, was previously running 94 but went lower to try this out, aggressive ignition curve (21 @idle, 35 in by 2000RPM).

Rest of drivetrain probably gives me some room (and is forgiving), this is a street car (3600 lbs), but 4K converter and 4.10 gear, so off-idle and part-throttle the motor has some chance to rev up easily and not quite feel the load that may lead to detonation at lower RPM...at least that's how I interpret my results so far (may be off on this...).