13.3's to 11.8's to Forget it...

If you are referring to the pistons stock cast are pretty stout, at the horsepower/rpm level he will be at and as long as detonation is kept under control it would be fine. An engine builder put it to me like this (he was referring to nitrous tune ups and pistons):
cast piston you get one chance
forged you get a few
No I wasn't referring to the cast I was just referring to the low compression...