It was not an elevator bolt, or stove bolt, with the square at the base of the head.  Not ribbed like a wheel stud.  I was simply as shown in my sketch below.  If I remember correctly at the local hardware store there were two types: one was slotted and the other had an allen drive.  The allen drive was a better quality bolt.  I prepared the hole by gently tapping the metal around the hole inwards to accept the tapered head.  After it was "caved in" about right I turned a large drill bit a couple of turns with a half inch drill motor to true up the hole for a better fit.


For a spacer under the tank I cut two strips of quality rubber sheet about and eighth inch think, two inches wide, and placed them on the floor.  I used rubber contact cement to keep them in place.  It has been good because from time to time I actually spray water from a hose under there to keep it cleaned out.  Seems to work well.

For the body-to-frame I actually used the tread portion of an old tire (bias-ply nylon) rather than the sidewall.  It provided more rubber.  Here is a pic. 

For my mounting bolt under the tank, I took a normal hex head bolt and headed to the grinder.  I ground the head of the bolt down to about half of the original thickness.  For spacers, I used an old heavy, rubber mud flap off of a dump truck and cut it into 2" strips as shown on Bob Westerman's 3A site.  I think the mud flap even had the famous naked lady outline on it....

However, i had my tub on and off so many times I think I ended up leaving that bolt out for the final install.  My jeep is primarly for show and paved roads and I didn't think the tub was going to fly off without that bolt in there.  Plus, I had a nagging feeling in my mind that my "Bubba bolt" would work loose and end up rubbing a hole in my fuel tank.  Bad enough I'm sitting on top of 10 gallons of flammable liquid in a 60 year old tank.....I didn't want to tempt fate even more.

I just had another idea....maybe I'll use the old windshield-to-cowl rubber seal.....

Looking Good!  Really Good!!!

Pretty cool.   I love home a fab work.