i've had amazing luck with Transmission Specialties out of PA. their converter in my car drove amazingly well (as well as a 4500 stall can be with no lock up) and was super efficient with less than 3% slippage at the stripe. i highly recommend giving them a call and talking to Justin about what you're looking to do. i believe they're a bit nicer on the price than some of the other converter companies as well.