i'm running 7 psi of boost on my engine with 9:1 comp with a 250 just put a 420 on it and plan to run 7 psi on that also with stk gm heads that are flowed 2-holley 850's on both set-ups,never a problem for atleast 5 years now.

were running 9.1

I like what Im herein My 540 pushing 575 630 torque should gain how much with a 250 b&m at abt 5 lbs of boost . Another 100 hp maybe ?