This big bore cylinder and piston kit contains S&S 4-1/8" bore cylinders and forged pistons, rings, wrist pins, head and base gaskets. Pistons are dished dome design intended for use with stock cylinder heads. The cylinders are machined with the stock bolt pattern and are intended for use in stock crankcases of 1999-'06 big twin engines. Designed for 4-5/8" stroke flywheels, resulting in 124" displacement. Cylinder finish is a durable wrinkle black powder coat. For best performance, appropriate camshafts, performance air cleaner, performance exhaust and fuel system tuning are required.

**Crankcases must be bored to accept the larger 4-1/8" bore cylinders.