Ah ha! So it was that output shaft again!

Remember torque is what breaks stuff, not horsepower. Nitrous makes a shitload of torque when it hits, I wouldn't be suprised if you were getting 225tq or so out of that 150hp shot of nitrous.

I think Trans-Center sells a billet output shaft, it's about $350 from what I recall...

The problem is the output is like 27 spline and the input is 33 spline, it's considerably weaker.