This kit is a Grade 8 Stainless Steel ARP (American Racing Products) engine mount bolt kit for the Ford 351-400 V-8 engines. These bolts mount the engine mounts to the block. They are not only good looking, and don’t rust, but they are super strong for your high horsepower needs and have a polished finish. These bolts have a tensile strength of 170,000 psi. They have a 3/8 inch 6 point head and a .625 diameter flange for easier access in the tight spots. This kit also includes stainless washers.