All cylinder heads are new castings and complete assemblies with new- stainless steel valves, hardened steel exhaust seats, valve springs, valve locks and retainers. All GM cylinder heads utilize high performance screw-in rocker arm studs in place of factory press in rocker arm studs.Fits: 5.7L V-8 GM Vortec (1996-up) with press in rocker arm studs (with 8 intake manifold mounting bolts) and composite valve cover.