leveling the front

I want to level the front of my truck. 1999 GMC Serria 2500 4x4. Wondering what is involved. Do the cams on the torsion bars need to be released and rotated or can I just turn the bolts in?

You can turn the adjuster bolts in to raise the ride height, make sure to count the turns on each side to keep the truck level. The alignment will need to be reset, and you will loose some caster/camber adjustment, so the alignement will not get to the ideal settings. The truck will also ride rougher than is does now.

is it just sagging? you can use some rubber bushings in the springs themselves as a temporary adjustment.