Base Thread Size: 3/8 in.-16 Rocker Arm Nut Thread Size: 7/16 in.-20 Rocker Arm Stud Material: 8740 Chromoly Guideplate Locator Shank: Yes Rocker Arm Nut Thread Length (in.): 0.800 in. Effective Stud Length (in.): 1.900 in. Base Thread Length (in.): 0.750