RockerArm Adjt Screw, Girdle Adj Nut Set BBC Int 7/16" Stud, Stud Girdle Adjusting Nut Set for Big Block Chevrolet Intake w/ 7/16" Stud, None, With an overall length of 2.515", this stud girdle adjusting nut set fits intake valves on Big Block Chevrolet., Engine Rocker Arm Nut.