Feuling Rocker Shaft And Bolt Kit For Harley Feuling made the decision to source the best material and heat treat technique available to create the best rocker shaft on the market following a rocker shaft failure during road racing at Laguna Seca in 2020. Instead of machining away the entire end of the shaft as per the factory design, custom tooling was made to provide a countersink relief for the bolt or 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 shafts, 8 studs, 8 nuts Made in the USA