The However, S&S Cycle is an aftermarket company that specializes in high-performance V-twin engines and components, and some riders choose to modify or customize their Harley-Davidson motorcycles with S&S engines for increased power and performance. This may be done through aftermarket modifications, but it is not a standard practice from the factory. It's worth checking with the latest Harley-Davidson updates or contacting a Harley-Davidson dealership for the most current information on engine options and specifications for their touring bikes.