At 400+hp, What kills A904s?

Powerglides, C4s and 904s are rich men's toys. They all require a huge investment to not burn up. I think the op is under the impression that a 904 CAN'T make him as happy as a four speed, but the way he refers to it as a slush box tells me that he's never experienced a performance automatic. He should rebuild his 904 with 5 .061 red eagles in 3rd, kevlar band for 2nd, competition shift kit and different 3rd return spring setup if he's shifting at over 6k, and kd set up right. And when anybody asks me if there's a break-in period, I say kick the tires and light the fires.