i wanted to install side steps my 06 silverado 4x4 that are attached to the cab mounts, i think they're a little sturdier than the rocker panel mounted ones. especially on my truck, with 156K miles on vt roads that are salted ( the rocker panels don't look so good ). so i found a set of steps by Aries that had brackets that looked pretty stout. got 'em for under $300 on ebay. https://www.ariesautomotive.com/part/4445006 ( there's an additional strut not shown that adds resistance to bending ) on dis-assembly i found a few problems: the lower rubber bushings were shot, they were replaced with polythane bushings. the driver's side cab mount was rusty and starting to fail so i reinforced it with a mongo washer i ordered. 2 inch i.d. x 4 inch o.d. x 1/8inch thick. when the cab bolts on that side were out, i jacked up the cab a few inches, removed the upper rubber mount and installed the washer on top of the existing/rusty mount. upper bushing back in, lowered the cab back down, all set. the washer's size distributed the load nicely i believe. the cab bolts were rusty and necked down as shown, so they were replaced. phew! all done. above pic shows gm bolt # and washer.