You insert the Well-Nut from the outside of the car. You put the bracket on top of it, insert the screw, and thread it in and as you tighten the screw, it pulls the threaded portion that's inside the door panel back towards the outside causing the rubber to swell up bigger than the hole. Since you mentioned that your whole it's bigger than normal, you may have to buy a slightly larger Well-Nut than stock.
1973 L-82 4 spd
You insert the Well-Nut from the outside of the car. You put the bracket on top of it, insert the screw, and thread it in and as you tighten the screw, it pulls the threaded portion that's inside the door panel back towards the outside causing the rubber to swell up bigger than the hole. Since you mentioned that your whole it's bigger than normal, you may have to buy a slightly larger Well-Nut than stock.
Really appreciate it!
An alternate method is to use Heli-Coil threaded inserts; to be able to use the original size & type of bolts.
https://www.c3vr.com/member_uploads/39101_39200/39182/DSC_00172018915875r.jpg
I don't think a Heli-coil will work very well in a fiberglass door. ;)
1973 L-82 4 spd
So if I am reading this correctly I can install a passenger side mirror from the outside, no need to remove the door panel or the glass.
Yes. I put one on my 72. You use the template, drill 2 holes 😮, and use rubber well nuts that expand in the holes when tightened. No taking off the door panel.
Be sure you order the correct mirror for your year because it changed shape around the '75 model year.
1973 L-82 4 spd
I ordered the larger size for my car (both sides) for better visibility than stock.
Also, get the more expensive "GM Restoration" mirrors. The cheaper ones are Chinese junk and won't stay in adjustment.
77 large head… been on the shelf too long.