These frame boxing sets are designed to reinforce your failure prone factory frame. The kits have two options-- one will work with the stock motor mounts and front cross members, and the other works in conjunction with our Cummins motor mount kit and cross member. The standard kit boxes the frame rails in from the steering box to the rear spring hanger. Fabrication and welding are required! You must replace the factory front cross member when using our Cummins motor mounting kit while the stock motor mount options works with all the factory mounts and cross members. Say goodbye to frame issues and cracks, it also comes with machined DOM sleeves and grade 8 hardware for the steering box to reinforce that trouble prone area. Made in the USA!