I know lots of guys racing 904s but they are puting tons of money in them to make them hold up. Why bother wasting money to tuffen up a 904 if he is going to already have a 727. Spend the money on your motor. I can smoke a siock 904 in my Duster in about 20 min. Got sick of laying under it. If 904s are so nice how come they never put them behind a big block?