Quote: Thing is, by the time you buy some 906s, clean them; mag 'em; mill them; install new guides, valves, and seats; get a valve job; and enlarge the seats, you're halfway to a new set of aluminum heads.
Probably more, easily 2/3's, I don't know how many times people have come on here talking about the loss of heat from the aluminum equals lost power, instead of looking at the advantages looking for a reason to stay with the old tech...
