I have to chime in and agree with what most others have already suggested.
Knowing that leveling a truck with the torsion bar adjustment method "cranking up the bars" is going to be the least optimal way to fit larger tires, for every mechanical part in the IFS system including the steering rack and pivot points, but most optimal for a budget minded consumer who isn't doing 4x4 boosted launches down the 1/4mi or sled pulling
Keep in mind that the more you choose to address the weak parts that become weaker when "leveling" the truck, it gets more expensive.
Shock extensions at a minimum, preferred way to go being longer shocks.
Upper control arms will help gain you the travel you need to utilize the "comfort zone" of the shock, but aren't a necessity. They are nice though, depending on how you decide to mount the ball joint they can allow for more height if you are wanting to get aggressive with the set up
Pitman and idler arm support brackets are kinda a must on a stock rig in my opinion, if you don't have those get them, but would be on my must have list for leveling one of our trucks
Stronger tie rods are nice and beneficial in many ways and would be a part I would suggest for an optimal set up
So To "optimally" level lift one of our GM trucks I would suggest
Upper control arms
Longer, mono tube shocks
Pitman and idler support kit
Tie rod upgrade
This will get you the best ride, more responsive "planted" feeling steering, better braking control and the leveled look you are looking for, with the least amount, if any, in stock ride comfort. However, if you choose to max out the torsion bars in this, or any setup utilizing torsion bar adjustment for clearance, your ride will suffer, the c/v angles will suffer, and so will all the other parts and the front tires, just the same as if you just cranked the stock components, they just might last longer.
A well designed lift kit is really the best way to go for bigger tires or even "leveling" a truck, but lifting a truck come with its own set of disadvantages.
