Standard size replacement. Dimensions: 1.750″ head dia. x 0.3765″ stem dia. x 3.670″ Overall length. KPMI valves are manufactured in the U.S.A. by a dedicated staff and personnel with hands-on experience in stock and high performance. Quality materials and the latest CNC and 3-D computer modelling equipment make sure each and every Kibblewhite Precision Machining valve train component is top of the line. All Black Diamond valves are one-piece Stainless Steel forgings with a black nitrided finish. Repl. 18081-36.