A tcase drop is not normally even close to being enough to get rid of the vibrations caused by a suspension lift as tall as 4". I HATE it when shops sell 4" suspension lifts to unsuspecting SWB Wrangler TJ owners without telling them they are likely to develop serious vibrations until they get a SYE & CV driveshaft installed. I suspect they don't tell them because of how much more $$$ installing a SYE & CV driveshaft adds to the cost & that the customer may decide to do nothing. Once the 4" suspension lift is installed, they're stuck.
In the mean time, you can't just "live with" those vibrations which can start taking out the u-joints, seals, etc. I would drop that t-case down another inch until you can get a SYE/CV driveshaft. That additional inch should help a lot.
The front vibration could be nothing more than imperfect tire balance. The bigger thet tire, the more critical tire balance becomes.