Help Me Learn About Transmissions

I have a friend that has a Z T5 behind a pretty nasty 408. Thing will get sideways in third at 65mph. And that's with 3.55's. And then there is me, I've been through about 5 T5's in my various Mustangs, and ended up going to a viper T56, and it's lasted me almost 3 years now. THe big thing, honestly, is your driving style. But a bulletproof tranny doesn't hurt either

How much is a T-5 good for usually?

I think T5s are good trannies. My dads has 85K on it and runs in the low 12s with ease. Not once has it made any signs of wear, and also had the stock clutch at 70K with a bunch of low 13s on it, and was basically mint when it came out. He has only missed one shift (besides the time he ripped the shift ball off) and drives the car extremely hard! I have seen lots of stock T5s in the low 12s run perfect and show no signs of wear!

Basically it depends on the driver of how much power they can handle. A guy on Corral recently posted a 9.8 run on a T5... Tremec is stronger, its basically what you want to do with the car!