Can you give me the part number for this? It's the bolt that secures the underbody spare tire. I've temporarily replaced it with some 1/2" threaded rod, washer and stop nut, but I have to unscrew that completely to drop the spare--a bit inconvenient. You can click on the thumbnail to get a fullsized look.

 

here's what LMC has, not sure if it helps?
http://lmctruck.com/icatalog/fd/0028.asp

 

If it's too much trouble to find, just bend a ring on an allthread, weld on a big washer and cut it to length.

 

Check the local parts yard . I saw several just hanging there at my local yard. Bought one last year $5 . Good luck one search