Ok, I put together a 318 out of a 75 lebaron wagon. Compression is stock. Heads are mildly ported, valves are back cut at 30 degrees. I have a comp cam 268 magnum muscle kit (cam, lifters, springs, locks, seals, timing set) air gap intake, holley 600 cfm 4bbl. I think the cam is like 268/272...