Old Muscle
Member
I am building a 70 SBC 350. .040 over and stock stroke. Comp cam 12-366-4 w/1.5 ra. 113 ls, 487 In 483 Ex, 63 IVC. I'm using the original 186 CI heads w/ 202 150 valves. I opened up the bowls, blended the runners and polished the cc and runners. Shaved the heads about .028 and ended up with an average of 58.25 cc overall, lowest being 57.6. Using Speed pro H631cp40 pistons and Scat rods. The deck is at .017. My intention was to use a 26-30 head gasket and end up with mid 40's quench and around 11:1 SCR. When I purchased the cam I was told with the late IVC 11:1 would be no problem with 93 pump gas. After doing some research I don't think this will work. I plugged my numbers into the Wallace DCR calculator and confirmed my thinking. My delema now is to decide on what head gasket to use. A .041 head gasket would give me about 10.7:1 SCR, 8.64 DCR and .058 of quench or a .051 would give me 10.4:1 SCR, 8.4 DCR and 68 quench.