jones Z

I have a '71 240Z with a SBC 350. It is a crate motor that is really torquey. The paperwork says it has 386 ft lbs of torque and 330hp. Behind that is a NON WORLD CLASS T-5 from an '86 V-8 Firebird / Camaro. We drove it to hot august nights in Reno from San Diego (about 1,000 miles total) had no problems, except now the t-5 leaks from the bearing race located next to the input shaft. Since then, the transmission has been out of the car 3 times - replacing the input shaft seals, RTVing etc. trying to eliminate the leak... no luck. I am guessing something is messed up in there since the input shaft is kind of wobbly. I since then looked at a '93 World Class T-5, that I found on craigslist. The bolt holes did not match the bellhousing from my NON WC. I had heard that they should be the same. Is there different Gens for the T-5? On a different note, Can you rebuild a Non WC and beef it up to handle normal to aggressive street driving. Sorry for the wordy post. Thanks!