Well, its tough to get the trac bar to line up with the mounts after you have lifted the truck 3" and not changed the mounts or bar at all.
Typically we have to turn the wheel (this pushes the body left or right over top of the leafsprings), and see if we can get the bar in place. Over 2" though it starts getting real tough to hook it up.
Transfer that difference in length during the install over to daily driving...that short bar is trying to pull the axle over to the drivers side naturally, and the springs are fighting to stay directly under the truck. You end up putting more strain than necessary on the leaf spring bushings, and this bind can (im not saying it is in your case) make the leafs harder to cycle like they should (ride quality).
This is why you see so many trucks around 8" crabwalking...because most of the box kits are designed for 6" kits and ran on both 4"s, and 8"s also...at that height, the leafsprings have a lot more distance from the axle to the frame, thus more room for swaying either way... so the short trac bar wins the battle, and pulls the axle over.