These Big Bore cylinder kits are a simple solution to increase the capacity of your Twin Cam without changing the stroke, so using your stock crank. These cylinders feature increased fin area for better heat dissipation and are easy to install as they do not require modification of the crank case nor rebalancing of the crank. Kits come ready-to-install bored to size with complete pistons and head and base gaskets. Note: 2014-2016 Twin Cooled Touring requires the separate purchase of fmc-747430 head gasket set.