Superlift's Level-It torsion-key...
Superlift's Level-It torsion-key kits raise the vehicle's front end and accommodate 33s for most fullsize Chevy/GMC torsion-bar trucks and SUVs (and up to 37s for H2s). Compare the LT285/55R20 BFG T/A (32.5-inch advertised height) to the stock P265/70R17s.
Cranking up IFS torsion bars to increase fenderwell clearance for taller tires is an old trick. Unfortunately, this "free" lift limits suspension travel and compromises ride quality.
A better solution for leveling the vehicle's front and clearing taller tires is to replace the OE torsion-bar "porkchops" with reindexed ones. Although this method isn't free, the reclocked porkchops allow more liftability and additional suspension articulation compared to cranking up the OE adjusters.
Many suspension companies now offer reindexed torsion-bar adjuster-key kits. In fact, several even get the keys from the same factory. Truck owners should check to see if the aftermarket adjusters are cast or forged. The OE keys are cast steel, but quality aftermarket forged replacements are 25 percent stronger. They cost more but are worth it-hanging larger, heavier tires on the knuckles adds stress to the rest of the front suspension.
Full-line suspension manufacturers offer options for customizing their leveling kits. Available upgrades from Superlift include speedometer-correction provisions so that the powertrain computer and speedo receive accurate speed-sensor signals when running taller tires, and extended-length single- and multiple-mount front monotube shocks with available remote reservoirs. In the rear, extended shocks, add-a-leaves, and blocks are available should the truck owner want to retain the factory rake while adding larger tires-without the expense of a taller, comprehensive suspension system.
The Superlift Level-It torsion-bar leveling kit shown here can be installed in about two hours. Although professional installation is recommended because "loaded" torsion bars store destructive amounts of energy, the competent weekend-warrior mechanic armed with the proper tool should be able to do the job. Installation involves loosening the OE cam bolts so your wheels should be aligned afterward, and the headlights should be re-aimed.
Depending on application, Superlift's Level-It torsion-key kits provide 1.5 to 2.5 inches of adjustable lift. Superlift's website lists maximum recommended tire sizes for each application; torsion-key kits are currently available for many '99-'07 GMT800-platform Chevy/GMC/Hummer trucks and SUVs (six- and eight-lug), '97-'04 Ford F-150 4WD, and Dodge Ram 1500 4WD. The photos here show Level-It torsion-key highlights on a '00-'07 GM K2500HD.
 Superlift's standard Level-It...  Superlift's standard Level-It torsion-key kit comes with a pair of forged-steel adjusters plus hardened metric adjusting bolts. Shock extension brackets are included when needed. |  Once the front end is raised...  Once the front end is raised and secured, mark the upper control-arms' cam-bolt orientations, then loosen them. One torsion bar can then safely be unloaded using a special heavy-duty C-clamp tool (Superlift PN 40017). |  The tool is used to crank...  The tool is used to crank up the key so that the adjuster bolt and nut block can be removed. Then the bar can be slowly unloaded using the tool. |
 Before removing the OE adjuster...  Before removing the OE adjuster key, scribe an alignment mark on it and the torsion bar. Transfer the adjuster's mark to the Superlift key. |  Insert the Superlift key,...  Insert the Superlift key, aligning its mark to the torsion bar's. |  Coat the Superlift adjuster...  Coat the Superlift adjuster bolt with antiseize, load the torsion bar with the special tool, then tighten the adjuster bolt until approximately half of its threads show. Final ride-height adjustment and headlight aiming take place on the ground. |
 When required, Level-It kits...  When required, Level-It kits include front shock extension brackets. These attach to the OE mounts-no drilling required. |  Before: The slight factory...  Before: The slight factory nosedown rake is apparent. |  After: The truck sits level...  After: The truck sits level and increased fenderwell space fits a taller tire. |