Jim -

Not sure about the Extended Mirrors on large trucks, but the factory installed reinforcing brackets inside the cowl are probably the best way to locate the location for standard mirror mounting bolts.
> Recent post on location of mirror bolts

The instructions for mounting extended mirrors are in the 1951 Accessories Installation Manual.
++ It has instructions and diagrams for Right-Hand (Passenger) Installation.
++ The instructions for Left-Hand (Passenger) installation are pretty simple ... "For Left-hand Installation: Remove existing mirror bracket and use existing holes in cowl."
> 986441 REAR VIEW MIRROR BRACKET - TRUCK

Brad Allen posted photos and templates for the mirrors a few years ago, but the photos were lost when WebShots changed their photo hosting site.

I have a .pdf of the GM mounting template. I probably downloaded it from Brad. I can email to you if you want. Send me a PM with your email address. Not sure if it is accurate.

- Lonnie

- Lonnie
My '54 3104
Photos that I have shared on Stovebolt via PhotoBucket are no longer available. Please contact me if you want a photo from an old post.
lonniecook [at] aol [dot] com. I sold my '54 3104 12/12/2017, but I still visit Stovebolt.

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