I run 165 PSI in my 318 with tight quench and high swirl iron heads (302s), it runs fine on 89 in the summer heat and 87 in the winter and I run a 195 t-stat. More preasure and more octane would be a good thing. I am thinking about going from 9.5 static comp to 10.00 by swapping head gaskets from .039 felpros to .028 mopars that also have a smaller bore. My pistons are .005 below deck. My cam is a factory 273 2bbl cam. Also a thermo-quad carb to help keep the fuel cool. Heat crossover is blocked.

My dads geo metro when new had 220lbs cranking compression when new and never pings on 87