If you have an engine that has milled heads, forced induction, high compression, or one that uses an aftermarket camshaft, 23-830BK "Tru-Time" adjustable cam gears are for you. "Tru-Time" 23-830BK gears enable you to match the cam timing with your vehicle's state of tune by easily advancing or retarding the camshaft in one degree increments. Gain increased horsepower and torque without having to remove and change the camshaft. The 23-830BK gears are CNC machined from 6061-T6 billet aluminum and use grade 8 six point bolts so they can withstand repeated use. The laser etched markings are easy to read and precision cut teeth ensure that there will be no premature wear of the timing belt. IT anodizing has been laboratory tested to be the hardest anodizing process in the industry.