to eliminate the rear driveshaft as the culprit, remove it and drive it in 4wd (really front wheel drive now).
i'd lean toward it being a fully sprung issue...with the 882's.

 

very good advice! It worked for me... I had screwed up my driveline geometry from a 3" spring lift.

 

You need to be certain that the alignment and balancing were done properly. After the lift, the tech should have had to spend significant time adjusting the alignment - hopefully you got a printout of what was performed and can see that the alignment started out way out of spec and finished within spec. If no print out, my guess is that they may have only straightened the wheels and not done a proper alignment.

As for the balance, are you sure that was done properly? The only shop I trust my alignment and balancing to is my local Toyota Service folks these days. Been burned by others telling me they had the equipment....