The Motobilt MB4040 is a single spring perch that was designed specifically to be compatible with the Chevy Dana 60 front axle. The passenger side perch is cast into the housing and cannot be altered. The driver's side perch can be cut off and a new perch welded on. The Motobilt MB4040 wad designed so that once installed it is the exact same height as the passenger side perch that is cast into the housing. The spring perch is made from 1/4 inch thick steel plate that is laser cut and cnc bent for a precise fit. Sold individually