Crane's Screw-In Rocker Arm Studs Eliminate Press-In Studs Pulling Out At High Rpm and In High Valve Spring Pressure Applications. Made From High Quality Alloy Steel, Crane Studs Are Precision Machined and Heat Treated For Reliable Operation With Today's Valve Train Loading. Specially Machined Threads and Shoulder Area Assures Firm and Positive Rocker Arm Support With Minimum Movement Or Distortion. The 99148 Studs Are Used To Convert Chevrolet 60? V-6 80-94, 2. 8-3. 1L Engines With Non-Self Aligning 10Mm Stud Rocker Arms To Use Adjustable Narrow Body 3/8" Stud Rocker Arms Without Cylinder Head Machining. The 99152 Stud Is Primarily Used For Converting 1991-Up Chevrolet V-8 454-502 Gen V and Vi Cylinder Heads To An Adjustable Valve Train Configuration (With Factory Pushrod Guideplates) Without Cylinder Head Machining.Pit Stop USA offers Crane Cams Rocker Arm Studs (16) - Top: 7/16"-20, Bottom: 7/16"-14 99159-16 at low everyday prices. Be sure to check out all of our products from Crane Cams including Crane Cams Rocker Arm Studs.