Weird Vibrations Help!

You might want to measure your drive shaft angles and see if you can nail down the geometry. You should be able to tell pretty quickly if there is an angle that needs correcting.
Post up your findings and I'm sure we can determine exactly what size shims you need, if any.

 

Warped rotors would cause this. Or sticking drum brakes.

 

Worse in neutral, like coasting in neutral with the engine at idle??

 

Yes. The vibrations between 50-63mph seem to exaggerate in neutral beteeen those speeds.

 

Update: took my rear driveshaft out and drove it in FWD. Vibrations were seriously cut down (slight vibration through the gear lever and transfercase lever). Thinking I found the culprit.

 

Could it be a bad U-joint on the rear driveshaft? Did you check those?

 

Already had the u joint replaced, and the driveshaft lengthened a bit. Balanced 2 times!