Get a second person to sit in the truck and turn the wheel side to side. Crawl up under the driver side of your truck and look at the track bar end as the second person is moving the wheel. You should see the ball-joint end moving quiet a bit, may have some play in the bushing in at the axle side of the track-bar as well. They are the number one cause of the death wobble. I would suggest an adjustable track bar for that much of a lift. Don't forget to regularly check your front end joints by jacking up each side of your truck one at a time and sliding a pry-bar, rod, something of length and rigidness under the tire and pulling up on the bar as you hold the upper and lower ball joint to feel for excessive play. After that while it is still jacked up just wiggle the tire side to side and see if you have any play in the steering linkage. Side note, wheels bearings can be checked by wiggling the tire assembly side to side or up and down.