Welcome to the Z.
In my experience with 2" lifts, I would adjust your
caster all the way out and try it again. This means adjusting the shims behind the lower control arms on the front axle, so as to push the bottom of the front axle forward.
If you want to be sure before messing with it, remove the front driveshaft and take it for a test drive. Chances are your vibes will be gone and you will know the problem is in the front.
Let us know what you find.