Now S&S heads are available to be used with stock-style flat-top pistons Kits are fully assembled, and include stainless steel valves and high-lift springs Intake manifold and gasket kits are sold separately; gasket kits contain head gaskets, base gaskets and exhaust pipe gaskets (rocker box gaskets are not included due to the variety of available rocker box styles) Choose between 3-1/2" bore head gaskets 433-794 and 3-5/8" head gaskets 433-795 depending on cylinder bore Optimized for smaller displacement engines Slight increase in compression (8.8:1 in an 80" motor) Port design increases flow, while maintaining velocity Set up for .585" maximum lift EFI compatible Black powdercoat finish