.640" valve lift. IOG = gear drive cams with Inner & Outer drive Gears. Complete kit with installation hardware; bearings and gasket. For 95"-up with 10.5:1 to 11.5:1 CR (stock in S&S 124" engines). Easy Start Cams make starting easier by reducing the build-up of cranking pressure in the cylinders during starting. This is done by lifting the exhaust valve slightly of its seat; with a spring loaded compression release lobe inside the camshaft. After starting the compression release lobe is retracted by centrifugal force. The only difference is during starting since you will now be able to electric start your Big Inch engine effortless; without the use of big batteries and/or starter motors. A stock starter and battery is enough. When the engine is running the camshafts function as regular cams; without any loss in power; torque or anything else. Note: The required installation kit for Easy Start Cams are included in this complete (IOG) kit. It is separately available as replacement from S&S for this kit as 503566. Note: No Easy Start Cam grind is bolt-in for these 99-06 Twin Cam models. All will / may require clearancing and require high lift valve springs. Note: Not compatible with kickstart models. Note: Camshafts made before Jan. 2010 will require adjustable pushrods. Note: Below 900 RPM you may hear a clicking sound. Adjust idle speed to 1000-1100 RPM.