S&S 110 Sidewinder Big Bore Kit For Harley Twin Cam Features: S&S Cycle 4 big bore cylinder and piston kits boost 96/103 Twin Cam engines to 110 Complete kits include cylinders, forged pistons, gaskets, and instructions These bolt-in kits don't require any machining, rebalancing or engine removal, and include just about everything you'll need to complete the installation The biggest cylinder bore that can be installed in a stock crankcase without machining, balancing, or splitting the crankcase Note: Although not mandatory, S&S recommends adding an oil cooler to bikes ridden in warmer climates