Yea yea yea, that's the ticket.
Even though the 904 is lighter, the pounds saved are minimal. They are only a 10th quicker if your racing them and properly built.
If it's in a everyday car/street hot rod, I would also look for a lock up just for the extra push in mileage. Then again, depending how much the engine is built up...LOL, who cares about mileage.