Ramcharger vibration help

Sorry, it is 4wd. Parking brake is not dragging. I had the rear apart yesterday and drums come off easily. It has auto locking front hubs. Rear u joints have 200 miles on them, front shaft has about 35,000 as well as the front axles. All bearings were replaced at that same time as well. I grease every fitting each oil change.
This started about 1000 miles ago and is literally driving me bonkers trying to find it.
I did get new trans and motor mounts, but haven't gotten to that yet. Guess that could be the next in line.
Thanks