Bad vibration ??
Bad Vibrations??? I've heard of "Good Vibrations", but if you hum a few bars, maybe it'll come to me!!! Seriously, I believe the angle should be 4 to 7 degree's or thereabouts, and they usually shim the perches of the rear end with tapered wedges. I believe you could get them from Mancini also. Not sure if the pinion angle is going to cause a vibration, but I ain't saying it won't!!! Good luck, Geof