S&S Cycle SS106-3240 89cc Cylinder Head Kit Black for Twin Cam 06-17These S&S Super Stock high performance cylinder heads are designed for 2006 '16 engines with stock crankcase. They work well with engines of stock displacement , but are ideal for somewhat larger stroker or big bore engines up to 110". The 89cc combustion chamber provides a slightly higher than stock, but still manageable compression ratio in larger than stock engines. This makes them a good choice for touring bikes and other heavy vehicles. Machined