Tail / Driveshaft Angle..???

Eric's right. If it vibrates in park it's an engine balance problem. If it vibrates moving it's a driveline problem. If it does vibrate in neutral that is an engine balance problem and if you remove the starter and inspection cover you can roll the engine over by hand and you should be able to easily see if the converter has weights on it. they will be located on the front side of the verter between 2 of the bolts. They will also be exactly opposite of the counterweight on the harmonic balancer so if you put the counterweight on the balancer on the top the weights on the verter will be on the bottom.

If I remember right for every 1/4" you raise the tailshaft of the trans it will increase the output shaft angle by 2 degrees. You do need to get the angles right on the front and the back to make the U-joints last a good long life and if the angles way off it can cause a vibration. You also have to take into consideration how engine torque twists the rearend upward when setting the angles and that means if the car is just mainly street driven you don't need as much downward angle on the rearend as you would a racecar. I have mine set up with the trans. up 1 degree and the rearend down 5 degrees. 1 degree up on the trans. minus 5 degrees down on the rearend leaves a 4 degree difference while standing still. I plan on racing mine some so that's why I have that much angle but if you don't race 2 degrees difference is enough. BTW: when setting up mine I first tried the rearend 7 degrees down (6 degrees difference) and it had a little vibration while cruising so it is true that too much angle can cause a vibration.

BTW you can easily check the trans. output shaft angle by placing the angle finder on the harmonic balancer because it's a perfect straight line throughout the driveline.

And I'd like to add that if any shop want's to charge you several hundred dollars just to make a shim and install it under the trans. mount their rip offs. That's an hour job at most with $5 worth of metal.