Man, frame stiffeners are the biggest PIA install. Mostly because its designed to run on a brand new show room floor model that hasn't been beaten up at all. The flimsy stock frame tabs get beaten up pretty quick, and they make that install a real pain. But...having that on there will protect them for the long haul. For some of the older machines that have seen some abuse, I always just say to beat the hell out of it until you can get it to fit. Frame to frame variation isn't bad but isn't perfect, but the main issue is trying to get it on when you already have a little damage. The frame stiffener, a skid plate, and a winch would be the absolute first things I'd do to a brand new machine.