440 Source Aluminum Big Block Heads

a friend have them on 493 I used it
all summer long on the street

this guy is what I call the burnout KING
where I leave he s pretty hard on is car
so I woudnt think they are crappy
BUT he hade them check for valve guide
and evry thing before he install them
jthe guide was (tited) (sorry Im french)
didnt have enough clearance