S&S cylinder heads are really state of the art. Just the part you need to make your Shovelhead growl again. While stock heads use studs to attach the rocker box assemblies, S&S heads utilize 5/16-18 hex-head bolts. Rocker cover bolts are included with each complete Shovel- style head kit. Otherwise, S&S heads accept all stock-style components. Intake and exhaust ports are in the stock locations and are the same size as stock. Stock intake manifolds and exhaust pipes are easily installed with no modification required. S&S Shovel style intake ports feature a directional vane to route the incoming fuel-air mixture around the valve guide and valve stem for improved performance. At 1.940", intake valves are the same diameter as stock, but exhaust valve diameter (1.720") has been reduced by .030" to improve valve to valve clearance for cams with high TDC lifts and to improve flow. A stock-like hemispherical combustion chamber is compatible with all standard Shovelhead style pistons. S&S Shovel style valve train components are specifically selected for durability under contemporary, real life conditions. They are compatible with present unleaded fuels. Valve springs can handle .590" total lift, and are available with steel or titanium top collars. Heads are machined to accept cams with TDC lifts of .210" on both valves. Because S&S Shovel style heads have stock dimensions, they readily bolt on with a stock-like fit with no clearance problems with frames and standard Shovel exhausts. Complete kits include all gaskets required for installation except intake manifold seals. S&S Shovel style cylinder heads are sold in sets of front and rear. The heads are completely assembled with premium components. Installed parts include valve seats, guides, seals, valves, valve springs, collars, and keepers. Kits also include rocker cover gaskets, cylinder head assemblies, head and base gaskets, miscellaneous hardware, and instructions. Available for 1966 thru 1978 models for use with O-ring style manifold, or for 1979 thru 1984 models for use with rubber band style manifold.