Driveline vibration

Really hoping to get some help here. I’ve had a vibration at 70 that I can’t get rid of. It’s a harmonic growl vibration( whom whom whom). More so on decel but still present while normal cruising at 70. I had a bent wheel that was fixed, still there. I bubble balanced the rears still there, one still takes a lot of weight to get right. Now I’m onto pinion angle. I did notice that one of the thrust washers inside the u joint cup was missing. Drive shaft would move in pinion about .050 north and south. Put that in, still no change.
Engine angle is 1.5 down, drive shaft is 1 down and pinion is 3.5 pointed toward ground with shims that calvert said to put in. No change there. I flipped the shims which actually made it more pissed off just to see (pinion up). The only real change I’ve seen was when I moved the weights around on the wheels the frequency of the hum/ vibration changed.
At 70 I push the clutch in and it’s still there. Definitely in the back of the car.. any suggestions? All these parts are new. Drive shaft, 9” rearend, housing, axles, wheels..