I have used either Comp or PAC for a blown SB Chevy years ago that where 1.440 O.D., I don't remember the exact installed and open pressures but I'm sure they where above 225 Lbs. on the seats and over 500 lb. opened I think they where dual spring with a dampener.
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
