I bought a pair of sun visors for my ’53 but now I’m hesitant to install them.

Just screwing them to the head liner seems kind of weak. Do I need to pull the headliner to find the holes in the roof? Will I find holes in the roof?

I don’t want to be drilling holes in things I don’t have to. My goal is to enjoy the truck for as long as I can, then If they don’t burry me in it, it can go to another stovebolter to drive and enjoy.