I have seen a service bulletin for WW2 Canadian Chevs that described vibrations being caused by having the u-bolts that held the u-joints to the drive flange overtightened causing binding.
This bulletin applied only to open drive shaft types with the u-joints attached by u-bolts (as opposed to straps).
The remedy was to ensure no binding of the u-bolts in the drive flange, torque the nuts to 23-25 ft-lb and stake the u-bolt threads below the nuts in case they started to loosen.
