Gear drive. .594" intake; .594" exhaust valve lift. Camshafts come without inner & outer drive gears. Large displacement 103/110/124". Power band 2200-6250 RPM with excellent performance in heavy bikes. For 95" high compression engines upper RPM power. Works well with higher compression ratio but smaller engines require it. High lift springs; pushrods; lifters; carburetor / throttle body work; performance exhaust; intake & clutch work required. Note: These high lift cams come with smaller base circles and will therefore require adjustable pushrods to compensate for the additional length required. Note: Gears must be purchased separately. Installation is a simple press-on installation. If you have gears from your current; Andrews or S&S gear drive cam; these can be re-used or a new S&S set (531264) purchased. Note: Block-off plates 566113 are sold separately. These are required to block-off oil holes for hydraulic chain tensioners when gear driven cams are installed.