S&S Cycle High Output Super Stock Cylinder Head Kit Features: For stock 3-1/2 bore S&S Super Stock band style cylinder heads Stock like appearance, but flow much better than stock heads Heads come assembled with premium valves and S&S valve springs that can handle cams with lifts up to .590 machined for one spark plug per head Accept stock bore 74 or 80 cylinders Great upgrade for stock shovelheads Rocker boxes are fastened with 5/16-18 cap screws instead of the stock studs and nuts Natural aluminum finish Kit includes front and rear cylinder head assemblies, rocker box gaskets, copper head gaskets, exhaust gaskets, hardware, and instructions