Strong, lightweight Aluminum Pushrods manufactured from the best materials obtainable regardless of cost. MADE IN THE USA All parts are accurately machined, holding tolerances as small as .005" All steel wear surfaces are carbo-nitride heat treated for maximum durability and long life expectancy at high valve spring loads and high RPM. Fits 1964-1988 Harley Shovelhead FL, FS, FX, FLH & FLT Models (For use with Hydraulic Lifters) Replaces HD# 17904-66