The S&S Cycle 131" kit for 2017 and up M8 is the perfect sleeper package. Boost your engine displacement to get some big numbers at the rear wheel, without advertising it. The kit bolts in with no machine work required and keeps your bike looking stock for the "sleeper" approach. Our 131" kit includes all the necessary gaskets for the installation and if you want to tell everyone what you have, a new 131" badge is included for your cam cover.