[eschaider]

Pointing upwards can miscommunicate the positioning. The simple answer is yes; however, you want the front of the drive shaft to be higher than the rear of the drive shaft and both to be above and parallel with the pinion centerline. It is easier to think of it in terms of parallelism.

You want the crankshaft centerline to be parallel with the centerline of the pinion. They don't need to be in line, but they do need to be parallel, hence the angle finder commentary in my post #11. The vertical offset or displacement from perfect alignment will determine vibration and U-joint life.

A 10˚angle or offset will work quite nicely, providing a smooth application of power to the rear end. As you increase this number, the car will experience increased vibration. If you could get to a zero misalignment (perfectly aligned), it would not vibrate. However, it would prematurely wear out the U-joints. As they wore, they would then begin to vibrate prior to failure.