PRO/RACER harmonic dampers are tuned and built for ultimate performance in the PRO/RACE range of dampers, providing the largest boost to the raw performance of your engine, allowing you to squeeze out every last horsepower with ease. You can buy a PRO/RACER damper with the utmost confidence it will provide many years of reliable, trouble-free service. PRO/RACER harmonic dampers are manufactured to extremely high quality standards that are constantly monitored and checked at every step of the manufacturing process. Our quality levels in bore tolerance and the finish of the machined surfaces, far exceed OE standards. PRO/RACER harmonic dampers also feature accurate laser engraved timing marks at 0, 90, 180 and 270 degrees (except Ford models). Once assembly of the damper is complete, the entire damper is highly polished and then treated with clear protective coating providing an extremely attractive appearance. Due to the superior performance of the PRO/RACER range of harmonic dampers and significantly reduced vibrations, a greatly improved engine life is obtained using PRO/RACER dampers. Why spend thousands of dollars on a race engine only to ruin it by using a substandard harmonic damper. PRO/RACER offers two styles of dampers for small and big block Chevys; a Racer model and a Street model. The difference is that on the Racer model the elastomer is bonded to the steel hub and ring. This bonding is particularly valuable on applications where sustained high speed is present such as marine or circle track applications. The Street models are suitable for moderate performance applications on engines making approximately 350 to 400 hp. The special splines (see cutaway photo) enhance the bonding between the elastomer and the inner hub and outer ring which helps prevent any outer ring radial movement, a common problem on OEM stock factory dampers. If you would like to use a Street style damper on a 400 small block simply combine our #64262 Street small block damper with our #65266 Counterweight and you will have the proper combination for that engine. Cutaway shows internal splines which provide for twice the contact area, eliminating any possible