COMP Cams Upper Gear For 6506

Upper Gear for Hi-Tech™ belt drive system for Chevrolet Small Block, Oldsmobile Rocket, Raised Cam Big Block Crank Snout (#6506). Extreme application belt for high RPM and high compression durability. Infinitely adjustable Vernier sprocket for absolute timing accuracy. Unique belt idler system to reduce flap throughout RPM range. Designed to absorb crankshaft harmonics to guard against performance-robbing valve train instability. Utilizes a unique camshaft thrust adjustment system without shims. Includes double lip seals for long life and maximum crankcase vacuum. Different diameter idlers available for racers with align bored blocks. Ideal for serious street performance and race applications.