[69ShortStep]

Wanted to follow up thinking it may help someone in the future.

I ended taking my single piece driveshaft to a joint and clutch shop ( one recommended by Longhornman - thanks Andy ). They installed new lifetime u-joints, straightened and balanced the driveshaft.

It turned out being the best $98.50 I ever spent on my truck. It is driving great. My original problem started at 50mph and the vibration was terrible.

I would say doing driveshaft maintenance, tightening up some loose bellhousing/trans mounts and tightening up the panhard bar has eliminated 95% of the problem. There is still a tolerable vibration/shimmie from 50-55 mph but outside of those speeds it rides like a new truck.

Thanks to all for the help.