Feuling Gorilla Rocker Shaft And Bolt Kit For Harley Designed for strength, with nearly twice the strength of the manufacturer or our competitors' shafts. Features: Precision ground from 4140Ht steel Gas nitrided and final surface treated Kit includes shafts and ARP bolts Recommended for all engines and especially for engines running higher lift camshafts and heavier valve spring pressures Made in the USA