Topic: 1968 San Jose GT 390 Fastback Drivers Side Mirror mounts

[bullitt68]

Thanks Mike.  I'll be curious what you discover.  I'm wondering how are the factory inserts put into the door and how are they supposed to stay still, not rotate.  Seems that is a common problem. I also can't tell how to remove the factory inserts without enlarging the hole and beating up the door.  If you have any thoughts on either that would be great.

I was planning to grind the top off and then install the new rivnut

[dkknab]

If your originals do not spin I recommend running a #8-24 tap through them to remove any paint that might be there before trying to install the mirror.

My original inserts on the driver side both spin.  I purchased a nutsert tool from Amazon, the one with the long arms for leverage,  and was able to tighten up both of the inserts. I used a 10-24 tap to clean out the hole and reinstalled the mirror using 10-24 Phillips Oval head screws,  not the Phillips Oval head sheet metal screws that were installed originally.

[Bob Gaines]

My original inserts on the driver side both spin.  I purchased a nutsert tool from Amazon, the one with the long arms for leverage,  and was able to tighten up both of the inserts. I used a 10-24 tap to clean out the hole and reinstalled the mirror using 10-24 Phillips Oval head screws,  not the Phillips Oval head sheet metal screws that were installed originally.

From the factory the outside mirror used the posi drive type machine thread screw. They have a counter sunk head like the generic mirror screws . Posi drive looks like a Philips cross head impression however they have a slighter different shape inside the allows for more torque to be applied without slipping. They are identified by 3 slash marks in between the Phillips impression . I believe that they are mentioned in the MCA rules. The picture I posted is to show the marks on the head. Disregard the flat head and sheet metal threads. NPD used to sell them but can't say currently.

[dkknab]

From the factory the outside mirror used the posi drive type machine thread screw. They have a counter sunk head like the generic mirror screws . Posi drive looks like a Philips cross head impression however they have a slighter different shape inside the allows for more torque to be applied without slipping. They are identified by 3 slash marks in between the Phillips impression . I believe that they are mentioned in the MCA rules. The picture I posted is to show the marks on the head. Disregard the flat head and sheet metal threads. NPD used to sell them but can't say currently.

That's interesting. They seem to be hard to come by.  When I search for 376770-s100 screw that is listed in the fastener spreadsheet and on the assembly manual page N8-8505 I come up empty.

[RoyceP]

I use these:


AMK Products P/N B-11557

[RoyceP]

Link: https://www.amkproducts.com/bulk-fasteners-products/?Product_ID=11557

[Bob Gaines]

I use these:


AMK Products P/N B-11557

Those will no doubt work but are not the posi drive given they do not have the markings. It all depends on if you are concerned about doing it the assemblyline way or not.

[dkknab]

How about these from AMK?

[jwc66k]

That's interesting. They seem to be hard to come by.  When I search for 376770-s100 screw that is listed in the fastener spreadsheet and on the assembly manual page N8-8505 I come up empty.

Simply put, 376770-S100 is the assembly line screw for 1967 and 68 Mustang (probably others too). It is also the the service replacement screw for 1967 thru 1970 Mustangs as called out in the 1975 edition of "Ford Car Parts" (aka the infamous MPC). Apparently it is not reproduced or available.

I use these:
AMK Products P/N B-11557

Check the size required.

How about these from AMK?

The picture didn't copy, but the screw is 382968-S45, 10-24X1.0 SST, chrome plated, Pozi-Drive. It should be the correct thread size, but is 1 inch long, whereas 376770-S100 is 7/8 inch long. It is the assembly line specified screw for 69 and up.
You still need a "nutsert" that don't "spin".
Jim

[Bob Gaines]

How about these from AMK?

it looks like you found some if you choose to be like the assemblyline.

[RoyceP]

How about these from AMK?

Yes with the #8 Head those ought to fit and work fine. The extra length will not hurt anything.

[Keith Stem]

382968-S45 10-24 x 1 Chrome over SS, AMK P/N B-12524

379556-S36 10-24 Riv-Nut, AMK P/N B-12928

NPD Part Number: 17696-4AK
Manufacturer Reference #'s: AMK F-802