I am pretty sure that most ppl here that rip off their driveshafts is due to pinon angle. When I 1st did my drop, it would slightly vibrate at 40mph. After the pinon shims, it was perfect.. and actually felt faster.

 

I don't vibrate at all with only 2" in the back.

 

mine doesn't vibrate with 2" out back either. are you sure the pinion angle is that far off. I would think you could go to at least 4" before it became a problem.

 

Try a 4x4 off road shop, they should stock them. 4WheelParts?