If you are lookin at this trans for your DSS 331 blown car....i think you should look elsewhere for something tougher. The T-5Z is basically a 93 cobra T-5 with a longer 2.95 first and a slightly longer .63 5th. The input and output shaft diameters are the same. I think the gear cluster is hardened and it has a steel bearing retainer. but i believe the trans is still only rated a 330 350 ft-lbs. They claim a 450hp rating if you dont race it....so that means nothing.
I would look into an Astro or Gforce T-5...or you need to look at the TKOs. They are the only trans that will really hold up to some abuse behind a 450rwhp car.