Mounting sport mirrors on 1972.

[terry b]

So i found a old thread on how to locate the holes for the sport mirrors. What i need to know is what size holes did the factory drill in the doors to mount the mirrors? Were the factory screws flat or domed on the head? Are you guys using stainless steel screws or crome? Where are you buying them? How are you holding the backing plates in place? Silacone? Can you get your hand in the door to hold the backer in place to start the screws? Thanks for any help.