I talked to some guys from Edelbrock at the last good guys in Pleasenton and they said the same thing but to o ring the heads if I use aluminum heads. Are you guys using iron heads? It was just a matter of blowing head gaskets. I've got a real nice Yamaha V star that I need to get rid of to buy this engine. I've got a 300 horse 350 and it just doesn't cut it. This site is great and you'll see the pictues soon. Thanks for everyone's info but don't stop.