Eng Rocker Arm Stud, Mag Rocker Stud 7/16" Base 7/16" Rocker, Magnum Rocker Stud Set w/ 7/16" Base Thread and 7/16" Rocker Thread, None, For applications with moderate lift and spring pressure, this High Energy stud set has a 7/16" base thread and 7/16" rocker thread., Engine Rocker Arm Stud.