Ramcharger vibrates after using 4wd

My 87 ramcharger started to have a vibration after I used the 4wd last week in a snowstorm. It's always smooth as silk until this. I thought I may have had a bad tire, but had 4 new tires put on and the problem is still there starts about 45 mph and continues on from there. First time I had to use 4wd in 2 years.
This spring I replaced the ball joints, rear driveshaft u-joints, Rear axles and all the bearings in the rear housing.
The front axle shaft bearings are fairly new, about 30,000 miles on them. I have and use a FSM and I assembled everything following the instructions in the manual.
The only thing I can think of is the front driveshaft with the CV joint in it at the transfer case. Its greased up and feels tight and spins freely.
Any suggestions? Have you Dodge techs ever run into problems like this?
Thanks