GM's K-35 series trucks with the heavy-duty chassis require heavy-duty tools to deal wih the larger torsion bar.  The larger C-frame opening on the 7822A accommodates the beefed-up torsion bar on these trucks holding it in place while you loosen or tighten the adjusting nut.  Also works on 1988 and newer GMC and Chevrolet 1/2-  3/4- and 1-ton pickups; S-10 Blazers  S-15 Jimmys  4WD pickups with 4.3L V-6 engines; and 1991 and newer Olds Bravada.