The T10 (?) 5-speed conversion is the way to go, but you will have to get one of the units designed specifically for Camaros and Mustangs, as they can handle the torque.
I'd think you'd wanna search the web for tranny rebuilders who specialize in beefy versions of it. They're out there, for $$$.
800 HP? Quite a motor....
Cheers!
George
