Maverick R Pro Desert Chromoly Upper A ArmsThe biggest change that we made to these arms is the balljoint is traded out for a spindle pin setup. We gained an enormous amount of strength going from a balljoint that has a size of . 540" to a spindle pin with a size of . 800". Our spindle pin is made from a heat treated 17 4 stainless steel and the uniball is an FK WSSX14T. Chromoly sheet metal increases the strength of these arms and the added strength not only comes from the material used, but