S&S 590G GEAR DRIVE CAMSHAFT KIT- 17+ M8 ModelsS&S 590G GEAR DRIVE CAMSHAFT KIT '17+ M8 Models The 590G cam was designed as an all out Horsepower Cam for 124 and larger engines. Big lift lets your big mill breathe high into the RPM range! Kits include all required bearings, o rings, and hardware Gear drive cams provide improved valve timing accuracy Eliminates the chain tensioner Requires high lift valve springs and adjustable pushrods Crank run out must be 0. 005" or less Made in the USA