My friend just replaced his blown GSR diff with an ITR LSD. The car now pulls very distinctly to the right under throttle. Sometimes even when decelerating. Would improperly shimming the diff cause this?

Also. Another concern is that the tranny has a 'whirring' noise when decelerating. And it gets fainter to the point where it's barely noticable when the clutch is pressed in. Accelerating and just a hint of throttle take the 'whirring' away. Does this sound like the input shaft bearing?

 

Bump.