Revolution aerospace-grade all-aluminum cylinders with nickel-silicon-carbide electroplated bores which means NO SLEEVING; allows larger bore sizes and less friction for more horsepower, lower temps and a longer lifespan. Monster power in a package thats tested, reliable and, most importantly, really big. Includes Wiseco forged pistons with rings (that are specifically designed for optimal compatibility with Revolution Performances cylinders), wrist pins, circlips and high-performance head and base gaskets. Available in four finishes: natural silver, black, black with highlighted fins or granite (matches the engines of Screamin Eagle models). Replacement head and base gasket sets available separately.