With the car in the air, grab the front driveshaft yoke at the front u-joint and see if it will move up and down inside the trans end. Any up and down movement of the shaft inside trans is too much and indicates the tailshaft bushing is bad.

Onto the rear end. Hold, or have someone hold the tires from turning, trans in neutral, see how much the driveshaft can turn in both directions before it is stopped by the wheels. How much can it turn, total of both ways?

One more thing you need to check on the rear end. You stated you could hear a noise on one side of the car, On that side of the car, put a socket with a ratchet on the U bolts holding the axle to the rear end and see if the u bolts are loose. The torque on the u bolts is not very high, but the nuts should at least be snug and resistant to tightening. Looks u bolts will let the rear axle rock on the spring and give you a clunk. If they feel loose, look up the specs and torque all the nuts to spec on both sides.

Let us know what you find. Gene