This kit is a Grade 8 Stainless Steel ARP (American Racing Products) bellhousing bolt kit using 6- 1 1/2″ bolts for the Ford 351-400 Modified engines using a C-6 automatic transmission. 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 1/2 inch 6 point head and a .750 diameter flange for easier access in the tight spots. This kit also includes stainless washers.