The torsion bar setup is a bar that reaches from the front suspension to a crossmember somewhere underneath the cab (it varies from vehicle to vehicle). There is a bolt associated with these two bars that lies directly underneath the crossmember. This bolt either adds or releases tension and can be adjusted to either raise or drop a vehicle's front ride height. You raise/drop the vehicle by adjusting this bolt on each torsion bar. Some people recommend that you buy a kit which will replace some of these components that will lift the front of the vehicle and keep the correct geometry. Make sure that everything fits fine when you adjust the torsion bar so that nothing is compromised such as the brake lines being overstretched. Don't just assume that your brake lines are fine at regular ride height after adjustment. Make sure you check that the lines are fine with the suspension's full travel.

 

I put a ready lift 2.5 in. leveling kit on mine and raised the back 1.5 in. and it sits perfect with 33's

 

I just wanted to see if there was any difference between a 98 silverado and a 99 incase i did get that kit. Im just not able to find one for a 98 z71