Feuling Rocker Shaft Set For Harley After experiencing a rocker shaft failure while road racing at Laguna Seca in 2020, Feuling determined to acquire the best feasible material and heat treatment procedure to build the best rocker shaft on the market. Instead of cutting away the whole end of the shaft as per the factory design, custom tooling was produced to give countersink relief for the bolt / nut head. Features: Precision ground from 4140Ht steel Gas nitrited & final surface treated Recommended for engines running higher lift camshafts & heavier valve spring pressures Sold as set of 4 Made in the USA