Allows upgrade of the ’99-’06 Twin Cam (except ’06 Dyna Glide) to the newer roller-style cam chains and replaces the spring tension cam chain adjusters with the later-style hydraulic adjusters for longer life. Cam grinds listed are designed to be used with stock lifters; they require the installation of a ’07-’17 cam plate, oil pump, cam sprockets and chains, and both hydraulic chain adjusters (these parts are not included and must be purchased separately). A list of required components is supplied with each set of cams. Performance should be similar to earlier bikes with the same cam grinds. Made in the USA. ’99-’06 Twin Cam motors (except ’06 Dyna Glide) cannot use the ’07-’17 cams, as the bearing journal on the earlier motors is .875″ in diameter and the ’07-’17 cams are 1.000″ in diameter. The “N” series of cams feature the .875″ bearing journal, yet still accept the new style cam support plate.. ’99-’01 model motors require Andrews rear cam sprocket . ’02-’06 models must use the stock rear cam sprocket, OEM #25728-06.. Installer must check coil bind, valve-to-valve clearance and valve-to-piston clearance..