ATI Super Damper has become one of the industry's standards in harmonic vibration control, combining two dampening surfaces in one unit. At 6000 RPM, digital vibration tests proved the ATI Super Damper to be 30% more effective than original equipment style dampers. ATI Super Damper consists of an outer shell, inner shell, crankshaft hub, and eight individual elastomers. Reductions in torsional vibrations provide increased horsepower while improving engine durability. a properly designed damper also removes the twist from the crankshaft while stabilizing camshaft and ignition timing. The Super Damper is also available with an aluminum shell which is considerably lighter than STOCK units while providing 30% more inertia weight.Pit Stop USA offers ATI Super Damper® Harmonic Damper - SB Chevy 400 - 7.074" Diameter - Steel - External Balance 917080 at low everyday prices. Be sure to check out all of our products from ATI including ATI Harmonic Balancers - Small Block Chevy.