About Heads
Yea, what he said. Unless your going to do some type of class racing and head must be stock but OK for mods, over 300 cfm is possible, but that requires some of the most absoulte nutty-est mods going. And of course, crazy money spent on it.
Anyway, the stock heads flow around 190 - 200 cfm on the intake give or take a few cfm on ethier side. The better old tyme X head will flow 10 above the others.