[Michael C Henry]

You are talking About a 5/16" bolt or stud. . If you take full advantage of the depth of the original hole, drill it out and tap it corectly and straight for the Heli-Coil. It will take more than the load needed to hold and seal your surge tank. The ARP SS carbruetor stud Have a rounded ball end for starting the nut. You can slide the surge tank over the studs with gasket applied, and everything will stay inline.