Spare tire carrier - what's wrong with this picture?

[72malibu]

Restoring my dad's 75 C15 for him.

I can't seem to find a photo showing how the spare tire carrier mounts to the frame.

I think the slotted hole on the passenger frame rale is where the long bolt with the welded-on rectangular head goes, but what's to stop that bolt from turning when I go to tighten the special nut under the bracket? The slot seems too wide to keep the bolt from spinning. Something doesn't seem right.

[kwmech]

Put a 3/8 bolt in one of the small holes?

[72malibu]

Originally Posted by kwmech

Put a 3/8 bolt in one of the small holes?

Yeah, we were thinking about that, but wondering if we did something wrong?

Also, does anyone's truck actually have the rearmost crossmember of three in this photo from the LMC catalog? I don't see it in any of the photos of trucks online, and nobody seems to sell it. But it would bolt into those two empty holes.

[kwmech]

I've found you cannot really go from the pics as they seem to be generic and/or approximate