Product Description Specifications Made from hardened steel, these locators use an inboard locating shoulder to center the seat and hold the spring in place. The 4731 features a 1.340" OD and a .570" ID that works well with our 26921 and 26926 dual valve springs. Category: Engine Components>Valve Springs, Retainers Core: N LTL: N MPN: 4731-16 Proposition 65: Y Special Order: Y