OK, we need a little more info. tell us about....
Track bar. Stock? drop bracket? anything else.
Steering linkage. Stock inverted Y? converted to anything else (TRO, heim)?
Steering box. Manual, stock power steering, F150 conversion?
Any problems before the lift?
Have you tried setting the wheels straight ahead, remove the pitman arm, center the steering box (all the way to one side, count the turns of the wheel to the other side, then put it in the middle) and reinstall the pitman arm?
Are the tierod ends maxed out in there angle?
And if you can, attach a picture of the front of your truck looking straight at it. Don't need any close ups, just tire to tire and bumper to ground. Pictures tell us a lot.