[tincan1966]

I learned from a previous project that driveline vibrations can be associated with the angle of the trans and pinion. Regardless of either 1 piece or 2 piece, the trans and pinion angle have to be the same.
I learned this after finding out the previous owner of my '69 C30 had shimmed up the trans mount about 1/4".
I found a good website that explained it all, I wil try to find it again and post the link