Now, racers can take their model's Original Equipment 110 cubic inch motor to a full 117 cubic inches without removing the engine from the chassis. The Screamin' Eagle team has engineered a 4.125" Big Bore Cylinder and Piston package that increase the internal bore from 4.0" to 4.125", without increasing the outside diameter of the cylinder spigot. The cylinder slips into the existing case bore without modification. Have you already installed a CVO™ Stage III performance kit on your CVO 110 Twin Cam motor? If so, you can retain that performance investment and combine those components with this kit. This kit will add a whopping 7 cubic inches of displacement for more torque throughout the RPM range. The kit includes front and rear cylinders, system-matched pistons with rings, and cylinder head gaskets. All EFI models require ECM calibration (priced separately). For race application only.