I bought a car put together by a dealership mechanic. the motor was 3 degrees down, and the pinion was 4 degrees down. I redid the lowering blocks and put the needed angle on them to make it right and didn't even notice any difference as far as vibration. I'm sure the u-joints would have thanked me if the could have though.
OK, didn't wanna leave you guys hangin'. I wound up raising the motor/trans combo an inch or so and dropping the tailshaft with a 3* downward angle which matches up perfectly with the pinions 3* upward angle. I'm good to go! Thanks everyone for all the valuable insight!! Blasted: Still waiting on the adjustable motor mount pics! They sound pretty cool!