How big of a lift? Did you install a raised steering arm?
Here's what you need to do to "center" your steering wheel:
1) Drive your truck in a straight line for a good 20 feet.
2) Park your truck and turn it off, but then put the key in the "run" position to unlock the steering wheel.
3) Loosen the two bolts on the drag link (piece going from steering arm to steering box) and turn that adjusting sleeve one way or the other to lengthen/shorten the draglink. I've found a plumbers pipe wrench works really good for this.
4) Turn that adjusting sleeve until the steering wheel is "straight".
5) Tighten bolts on adjusting sleeve.
6) Make sure that you actually have the center, and you're not one full revolution off of it. Check for this by starting from your "centered" position and turning until the wheel locks to the right. You should get the same amount of steering wheel revolutions going from center to left lock as well.
7) Test drive to make sure you're happy with how "centered" you've made the wheel...make adjustments accordingly.
