theres a bolt on each torsion bar where it ties into the cross member of the frame. When you tighten these bolts it turns the arm on the end of the torsion bar. this puts the torsion bars under more torsion and raises the height if the truck. just make sure to mark your socket or bolt so you can count the number of times you turn each one. you want to make sure and turn each one the same number of times so that the truck sets level from side to side.
you would need to have an alignment done as you would need to have done with a leveling kit. that will take care of the tire wear. and if your only raising it enough to level it, the ride wont be that bad.