As others have said, the track bars are NOT needed.
I've said this before, The only way that you will notice any ill effects from remvoing the track bars, is if the rest of your suspension is worn out.
Leaf spring suspensions do not need a track bar, the leaf springs locate the axle, as well as support the weight. The problems arise when the spring and shackle bushings are worn(at which point, they should be replaced, regardless of weather you're running a track bar or not.). With worn bushings, the springs can then move side to side (pivot around the bushings), which will let the axle move side to side, and make the steering feel loose or unresponsive.
For example, I'm running a 3" suspension lift, and removed both track bars, as well as the sway bar, about 5 years ago, and aside from a better ride on the road, and better flex off road, there was no change in the way it drives.
maroon 1987 Grand Wagoneer. stock for now...