Roller Rocker Arms - Big Twin

Cast from 4340 heat-treated chromoly steel. Reduce friction in the valve train, providing more horsepower and less heat in the top end. Include 660 bronze bushing fit to .0007" - .0012" for the best wear resistance and oil control. Roller tip made from bearing-grade material to reduce valve guide wear and valve tip galling. Segmented parabolic pushrod cup reduces friction at pushrod ends, while putting the load on the outer perimeter of pushrod ends, with full oil pressure at pushrod tip. Set includes two each front and rear rocker arms. Made in the U.S.A..