The Stovebolt Site Forums The Shop Area General Truck Talk Mounting inner fenders to firewall on a 50

I thought I had all the bolts in the fender bit kit, but it looks like the inner fenders are mounted to the toeboards with carriage bolts due t the square holes in the toeboards? Can anyone confirm this and also suggest correct size? Thank you

On my 52 GMC there were rectangular holes in the inner fenders not the the toe board of the cab. These holes on the inner fenders are for rectangular captured nuts. There are 5/16 x 18 cap screws about 3/4 to 1 inch long that secure the inner fenders to the toe board screwed in from the cab side. Several of mine were missing too so I made replacements and welded them to the inner fenders.

Left side inner fenders have round holes, and there are captive nuts on the parking brake bracket for the 5/16 hex bolts.
The right side inner fenders have captive nuts as mentioned by Huck above, which take a special low profile headed 5/16 bolt, in order to not make a bulge in the floor mat. I have never seen this special bolt personally. I am not that picky about a fastener which no one will ever see, and a standard hex head doesn't seem to make a bulge in my floor mat even with a flat washer on it..
Carl