Wiseco K1686 3.508" Bore 10.5:1 Compression Ratio Domed Forged Piston Kit Fits: All Harley-Davidson 1200 Evo Sportster engines 1988-2003, 1100 Evo Sportster engines 1986-1987, all Evo Sportster engines and Buell models with stock 1200 heads 73 cubic inch (1200 cubic capacity) kit includes 10.5:1 compression ratio domed pistons, rings, circlips, chrome piston pins Each Wiseco piston is designed with the proper installed clearance to produce the most power, least wear, and best seal at running temperature, for each application Dedicated forgings are used for superior strength to weight ratio utilizing aerospace alloy with a dome designed for improved flame travel and detailed skirt shape and profiles for stability and smooth operation in the cylinder bore