OK. You will need to increase the preload on the torsion bars. This is accomplished by tightening the adjuster bolt for the torsion bar key at the rear end of the bar. I'm not sure if you'll need to hold a nut on top of the key while turning the bolt or not, but you MUST NOT USE POWER/IMPACT TOOLS TO DO THIS!!! HAND TOOLS ONLY!!!

Tighten the bolts a few turns each (keep careful track of the number of turns, so they're even), not too many at one time, then drive the truck a short distance. Just around the block would be ok.

Each time you get back from a trip around the block, park on level ground and measure the height of the top of the wheel opening to the center of the hub (it helps if you did this before making adjustments, so you know how far you've gone).

I usually count quarter turns. It just works better for me, but maybe not for you. It's important to keep the left and right ride heights close to the same, so this becomes a very tedious, time consuming project.

Make sure you go directly to an alignment shop after you get the height set where you want it. This modification will change the alignment settings you currently have. Don't get too upset if they tell you they can't get it back to spec without lowering the front. Just ask them to get as close as they can. About all you're worried about is tire wear and steering pulls. Make sure they understand that (but don't mention it unless they bring it up. No point in giving them permission to do sloppy work).

If you put mud tires on this truck you will need to rotate the tires every 2500 miles or they will wear out very quickly.