UMI 6429 bracket mounts rear fuel tank kit on 1973–87 C10 leaf spring trucksThe UMI Performance 6429 Bracket Add On makes our industry leading rear fuel tank conversion accessible for all 1973 1987 C10 and GMC squarebody trucks, regardless of rear suspension setup. If your truck still runs factory leaf springs these precisely engineered brackets, templates, and hardware allow you to securely mount the 6428 kit using factory frame railsno 4 link required.