Can anyone help me figure out the correct measurement for mounting a outside mirror on the driver side door and rear antenna (don't know what side) for am radio?

Probably help to know what year and model.

It is a 65 Chevelle 2 dr hdpt non ss malibu. The original owner took off the driver door mirror and antenna and covered up the holes. I have no idea why he did this. :confused: I have an am manual radio and would like to mount the antenna in the rear fender. The radio tech featured on this site shows this to be correct for my year. I have the original mirror (driver side), but don't know where to place it correctly.