driveshaft angles

Flat equals 0 DEGREES. The car is on a 2 post lift with tall jack stands under both rear axle tubes screwed up until the frame is off the lift so all the weight is on the springs. So the trans is at O degrees and because of the A500 trans cross member and close clearances in the trans tunnel it would be hard to change. That leaves shimming the axle up 3 degrees to make them parallel.

I'm not sure if having them both at 0 is ideal. I've always understood both the same.but opposite. Can you bring the tailshaft DOWN degree or two? Then bring the pinion UP?

What trans mount did you end up using? I know the poly mount is quite a bit taller than the GM factory two bolt.