Sorry Linda called me for dinner and I never got back to correct my post. the center stud on picture (1) between the two exhaust ports should be longer than all the others. in your picture it seems to be the same as the rest of them if it is the same there is no way to put a nut on it the manifold is to thick there. if it is used as a dowel pin there is no holding power to it. the center is stud is part # (2033570) the other 8 center studs are part # (203611) and the end ones are part #(200312). unless you have the 1 barrel carburetor then forget all I have written.