S&S Cycle SS910-0179 OEM Replacement Cylinder Kit Natural for Big Twin 84-99This replacement cylinder and piston kit contains S&S 3 1 2" bore cylinders and cast pistons, rings, wrist pins, and head and base gaskets. The pistons included in this kit are flat topped cast pistons designed to be used with either stock cylinder heads or with S&S Performance Replacement heads. Cylinders have a natural aluminum finish.