after replacing the gears, front axle u joints, and rear drive shaft u joints, getting some vibes at highway speeds, more potent under acceleration, still present (but less) coasting

Any help would be appreciated thanks

 

Driveshaft bent/out of balance.

Try rotating the driveshaft/U-joint assembly 180 degrees from where it is now. It may be out of sync from the rear gears.

Excessive wear on ring & pinion and/or gearset.

Bad/worn axle bearings.

Vibration can be difficult to track down. Hope this helps some.