Product Description Specifications With a 7/16" base thread and a 3/8" rocker thread, the Hi-Tech stud features rolled threads for maximum contact and a ground-flat top for accurate valve adjustment. This stud set has a 1.750" effective stud length with a .680" long base. Category: Engine Components>Valve Springs, Retainers Core: N LTL: N MPN: 4505-16 Proposition 65: Y Special Order: Y