Melling recommends new rocker arm screws with every engine rebuild. Old screws are subject to metal failure, screw stretching, and worn threads. Sews also tend to be lost or damaged during the rebuilding process. There is also a danger of metal cracking when the old rocker arm screw is removed from the head. Melling rocker arm screws are manufactured to high quality and material standards. Using new rocker arm screws assures proper installation and valve train adjustment. Additional Attributes: GTIN: 00729295225072 Material: Steel Grade Type: Regular Thread Type: Fine Extened Information: Emissions : Legal US Life Cycle Status: Available Only While Supplies Last Packaging: Quantity of Each: 4.0 Package UOM: EA Dimension: 1.5000 x 3.5000 x 1.5000 inches