I ran a 12.00 in my 3900# B'cuda 10.5to 1. I had heads ported by hughes engines the cam had 263/268 duration @50from hughes .They make GREAT cams 4.30 gears and an 800 cfm holly D/P and a 3800-4200 stall . i also ran loose rod bearings clearence .0027-.0030 ran great for many yrs.If you want ill get the specs of the cam for you,it was very streetable.