JIMS® Roller Rocker arms are made from aerospace quality 4340 chrome moly steel, CNC machined and specially heat treated for durability. Critical areas of the arm are strengthened and material is removed where not needed for lighter weight. A roller tip made from bearing grade steel is incorporated to reduce valve and guide wear and 660 bronze bushings are used for stability, longevity and strength. Available for EV and Twin Cam® engines in stock 1.625:1, or higher 1.745:1 ratio for additional lift at the valve (modifications required). Shovel arms are 1.5:1 ratio. Uses stock or JIMS replacement rocker shafts (not included).
JIMS® rocker arm shafts are perfect for rebuilds or new construction, precision-ground right here in the USA. A special model for EV and Twin Cam® racing engines is available that is drilled and tapped on one end for grease fittings, designed to be used on engines that run “dry” top ends (no oil feed to the rocker arms). Sold each.