vibration after 3.23 to 3.91 swap

gear swap only. The driveshaft was purchased from Dr. diff a while back. 1350 u joints with nut style straps.
Come to think of it pretty sure it did the same thing last time I had these gears in. (so that means its done it with a different block, 4 speed trans, different drive shaft, 904 trans, 3 different converters.........................)