Revolution Performance Bolt-On Big Bore Kit (85in. Flat Top) - Bore 3-9/16in. - 9.0:1 Compression - Silver RP201-213WRevolution 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 True bolt on kit that delivers major power with no machine work required Also includes Wiseco forged pistons with rings (that are specifically designed for optimal compatibility with Revolution Performances cylinders), wrist pins,