I'm about 10.7CR now on my all aluminum LS motor. I have forged pistons and rods, high end fasteners all around, so even with the nodular crank, it should be able to handle 600+WHP all day long without breaking a sweat. I'd never even really want that in a street car honestly, but just curious, how many pounds of inter cooled boost from a centrifugal blower it would take with 91? I'm thinking not whole lot, maybe 6psi max.