Replacement 4-1/8" Bore Cylinder and Piston Kit With Stock Bolt Pattern For 1999-2006 Big TwinsThis replacement cylinder and piston kit contains S&S 4 1 8" bore cylinders and forged pistons, head and base gaskets. The cylinders are machined with the stock bolt pattern and are intended to replace cylinders of an S&S 111" Hot Set Up Kit for stock crankcases. The finish is a durable wrinkle black powder coat. **Crankcases must be bored to accept the larger 4 1 8" bore cylinders.