What to do to make a T1 tranny handle 300 FtLbs of torque?

[tdc911]

I did check the code and it is an AV box. Does the bus gears fit in the 181 box without changes? Does anyone have some experiance with the quaife diffs? I know you can bye them with t1 splines or t2 splines. Wich one is the best? The greater flange size doesn't matter because I have the porsche 944 turbo arms so I need them anyway. THx for the advice.

Tom