Wiseco K1757 4.000" Bore 10.5:1 Compression Ratio Flat Top Forged Piston Kit Fits: All Harley-Davidson Twin Cam 88 engines 1999-2006 with 4-3/8 inch stroke crank, Twin Cam 96 engines 2007-2012, Twin Cam 103 engines 2010-2012 110 cubic inch (1802 cubic capacity) big bore kit includes 10.5:1 compression ratio flat top pistons, rings, circlips, chrome piston pins Big bore cylinder or resleeving required with Wiseco PN: 3209FA sleeve, crankcase boring required, compatible with Screamin' Eagle cylinder heads (starting in 2011) 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 Utilizes the new ArmorGlide skirt coating, the ultimate in toughness, lubrication, and bond technology working together to minimize friction, maximize horsepower, providing improved wear resistance