I built a 318 basically the same w/ KB 167s and 302 heads but I ran the pistons .002 out of the hole with .039 gakets. I ran it on a stand and it's really crispy. The cam is Comp 256XE. I am putting it in a 65 Valiant with stock manifolds, dual exhaust, 833 OD, and a 8-1/4 wih 3.21 gears. I have a few issues with the clutch, but hope to have it together by the summer. Am hoping for 25+ mpg on the highway too. This is a great thread. More real world results please!