Product Description Specifications Hardened and black oxide coated for durability, this flat two-piece adjustable guide plate is designed for Chevrolet 265-400 Small Block and Ford 289-351W engines with 7/16" studs and 5/16" pushrods. Category: Engine Components>Guide Plates Core: N LTL: N MPN: 4835-1 Proposition 65: Y Special Order: Y