seen here, this specialty head stud harware provides twice as much surface area of load compared to the conventional hardware so often seen in the Industry. These washers distribute the load over a larger area preventing and distortion or movement of the aluminum on the cylinder head that is so common with the current Olds hardware offered today. These washers are .187 thick and are .513 i.d. with a 1 inch o.d. Thats a lot of surface area. Proven and tested, they work! 20 washers to a set.