This S&S Cycle 124" big bore/stroker Hot Set Up KitŪ transforms a CVO engine into a 124" monster. This kit includes S&S 4-1/8" bore pistons, big bore cylinders finished in Stone Gray powder coat that matches the factory finish, a dynamically balanced 4-5/8" stroke three piece flywheel assembly complete with S&S heavy duty connecting rods and intergal mainshafts, S&S 640 gear drive Easy Start camshafts, S&S chromoly steel adjustable pushrods, S&S premium tappets. When installed the kit yeilds a 124" engine with a compression ratio of 10.5:1 with the stock cylinder heads. Although the engine is .960" taller than stock, there are no frame clearance problems, and a stock EFI Throttle body will fit because the manifold mounting surfaces of the heads have been specially machined to fit a stock length manifold. No fuel or ignition system is included. However, for the best results, a larger EFI throttle body, performance intake and performance exhaust are recommended. The EFI system must be recalibrated. Although not mandatory, we recommend adding an oil cooler to bikes ridden in warmer climates.