70 road runner rear bumper guards

I'm wondering if anyone has a diagram with the location for the 70 satellite, road runner, belvedere, GTX rear bumper guards. Also looking for advice on drilling the bumper without screwing it up. Thank you!

No diagram.....here is a photo of my car with them.

Thanks! They appear to be centered with the edge of the trunk line. Did you add them to your car or was it originally equipped ?

Original equipment and documented on the window sticker. They do appear to be centered on the trunk lid edges.

pretty much on the panel seam