Due to the variety of makes and models of rocker covers and rocker arms available, the rocker arm end play may have to be adjusted. End play has to be set at .003" to .015" (0.08mm to 0.40mm). We offer hardened shims in the sizes .012" and .020" (0.30mm and 0.50mm) for proper end play adjustment. Fits 1984-1999 Evolution Big Twin, 1986 to present Evolution Sportster and 1999-2017 Twin Cam. Sold in 10 packs