oil pan

This isn't my engine but it's the location in question. It's the back of where the oil pan mounts to the engine next to the rear main seal. Where does this hole go? It goes all the way through and doesn't stop like the 1/4" ones. I'm asking because I broke a plastic bolt off in it while trying...

Never Installed / Still in the box 97-02 TJ skid Had plans to mount this, but after putting a dynatrac front axle in, it won't bolt up without modification ( which I don't plan to mess with). Link for details...