My '04 Suburban 1500 4X4 has Option Code FK2 & FK3 (Adjustable Torsion Bars L&R). Are these truly 'adjustable' or are they subject to the same stresses as stock when they're cranked up? All I want to do is level the truck and there is only about an inch difference from front to rear...however, it's enough to bug me. I'm running BFG All-Terrain T/A KO LT285/75R16 w/o any rubbing issues, but I would just like to level it. I know the issues involved with cranking up the torsion bars, but am looking for that elusive inexpensive fix as opposed to installing aftermarket torsion keys. Thanks.