I agree, the cam is a bit small for the rest of it. The 268 would be much better, along with a 700-750 cfm carb, but if that thing isn't decked, it's still not going to be great. IIRC, my deck height varied almost .030 front to back before I got it decked, with the deepest one being over .030 in the hole. After decking, they are all something like .002 out of the hole.