I ran into this problem on the last lift i did also. ended up being the caster setting on the front axle. If you did not replace your lower control arms then thats the problem. The lift throws off the front caster setting by pulling the axle torwards the rear of the truck. get some adjustable lower control arms and take it to get an alignment.

97 Wrangler Sport, 31" BFG All Terrain, .30 over 4.0L w/ Comp cam, P&P Head, Banks Header, Throttle body, chip.