Check for slack in the transfer case chain.
Also, there is a mount attached to the transmission that supports the exhaust system. It tends to crack in half, and can cause clanging noises with throttle and speed changes. If it is broken, you will only know by getting under the jeep with a strong flashlight and grabbing and moving the exhaust in that area. It hardly moves, but will still cause noise.
Carter BBD feeding 4.2 Nuttered 6 banger = 22 MPG Hwy
If it was easy, everyone would be doing it.