904s have too many limitations to get them to handle 400hp. Maybe start with a 999 and build it retro...There are too many people making money off C4 and 904 transmissions and they keep up the hype that they can be built to handle 900 hp etc, but we're talking $4-5k for a real one, not something with a couple sets of reds and a kevlar band with billet servo...Anybody who has compared a 904 to a 727 and a C4 to a C6 would have an understanding of the differences between a money pit weakling and a stock trans capable of 400 hp.
