Aem tru-time adjustable cam gears increase horsepower and torque without having to change the camshaft(s) and are must-have items for engines that are milled, forced induction, high compression and/or utilizing aftermarket competition cams. our gears enable users to match cam timing with their vehicle’s tuning state by advancing or retarding the cam profile in one-degree increments via true laser-etched markings. precision-cut gear teeth ensure no premature wearing of the belt surface and aem’s anodizing on the gear teeth is lab-test proven as the hardest anodizing process on the market. aem tru-time adjustable cam gears are available in a multi-spoke, five-bolt design for most vehicles and our classic full-faced, three-bolt design for select applications. five-bolt cam gears have an “8” in the suffix (23-8xx), and three-bolt cam gears have a “6” in the suffix (23-6xx). all aem tru-time adjustable cam gears are sold per gear, dohc motors will need to buy quantity: 2.