There's more to it than just the head, you also need the special
headers made for that head, the special Y pipe for the headers, the
HUGE original carb, the Cam with high lift & long duration. Just the
head won't do much for you.
The guys at B&B in Washougal have the high dome J&J pistons, big
carb, and I forget what else, but that car flies. I wouln't worry too
much about the crank, the compression should still be at stock specs.
Miles