Product Description Specifications With a needle bearing fulcrum and a roller tip, our die cast aluminum rockers decrease friction and improve horsepower. Featuring a 1.5 ratio, this rocker fits Chevrolet 265-400 Small Block w/ a 7/16" stud. Category: Engine Components>Rocker Arms Core: N LTL: N MPN: 17004-1 Proposition 65: Y Special Order: Y