Before spending a lot of investigative time, I'd put the two best tires on the front and have them dynamically balanced. Then I'd get a front alignment. Then road test it in the same conditions that is now giving a woble. If it still wobbles, then I'd starting looking into a lot of things.

1977 CJ-7, fiberglass body, AMC 360 w/ headers, DUI ignition, Edelbrock intake and Holley 4150 carb, TF999, Dana 300, 4.56 gears lockers, York air comp, 4" susp lift, 2" body lift, BFG 35" M-T tires, Megashifter, AGR pump & box, REP8000 winch.