Broke off stud on my 340 utility with C135 engine. Drilled and tapped, first time I attempted this. Where can I find new Stud and nut?. I believe it is 3/8 X aprox. 2" course thread on one side and fine on the other. Also what is torque spec for manifold nuts and I looked at my Cub and the studs appear to be the same are they?