wing nut that is at the top of the spare hold down bolt

Did you all know why the lower wing nut is that large?

To make it tight. The spare holds the fuel tank straps from pulling the steel bracket through the tin floor. Keep it tight and no jumps with a full tank without the spare in place. Towed a couple A-bodies years back that lost the tank.

Just something to think about next time you fill up. LOL