Anyone know of a reputable place that upgrades these trannies? I would like to see it handle 450 ft lbs or am I dreaming.

 

Anybody?

 

That's pushing fairly well built 454 specs. I think the Super T10 will handle it for daily driving, and the occasional romp, just not sure there's anything you could do to a Sup T10 to make it handle that kind of torque on a regular basis.
Of course if that's the peak torque of your engine, and you're not running it to peak a lot, then it's not a problem.

 

Yeah,the Super T-10 is pretty damn tough as is,it'll take a lot of pounding.
Unless this is an out and out drag race car it should hold up for street duty for a long while.
I had one behind a built 427 in my '69,never had the car on a dyno but it had to be making some pretty big torque numbers.
I pounded that thing hard for a long time and never broke it.