I have a set of 68 X heads and after a .010" cut the chambers cc'd at 71 cc's.
JFYI Valve type seems to make a big difference cause I later switched to Stainless valves and then cc'd the chambers again and it dropped to 67 cc's.
Here was my heads flow numbers when stock.
intake------------Exhaust
.100-60------------50
.200-120-----------95
.300-167-----------131
.400-200-----------143
.500-205-----------146
.600-200-----------148
