On a 427 it goes on the inside center of the frame, and I think the same is true of the small-block cars. I believe they used tiny brass flathead screws, not sure the size. I didn’t want to drill into the frame so I actually cut the heads off two screws, then used silicone to attach the medallion to the frame and the screw heads to the medallion. I’d post pics but I don’t own that particular car any more and my current one has a mirror attached right where the medallion is supposed to go so it wasn’t an issue
