The pitman arm is a non wearing part on your Jeep, check the tie rod ends and the steering box mounting bolts. If the tie rod ends check ot ok and nothing else is loose in the front end, it may be a worn out steering box. I've found that adjusting the steering box will not really help and could make it feel even more funky.
Steering stabilizers will not cure or cause death wobble, they only mask the real problem that is causing death wobble. Oil pumps do not make pressure, they create flow. Bearing clearence and restrictions make pressure. It's the crank sensor.