I wonder if a guy could fit a length of pipe (8-10 inch diameter) in the RH frame rail opposite of the main tank, and weld ends on it to seal it up and make a mini tank? would only need 5-10 gallons to make it worthwhile IMO. put a T in the fill hose and run a hose over to this little aux tank, run a stock LP to pump it back. then you can steal this LP if yours dies on the road.
Like said above, all long beds have the big 34 gallon tank, but I see you figured that out.
So Leroy, the burb tank requires cutting the spare tire crossmember out, and installing the burb crossmember? how much cutting and welded was needed on the burb crossmember? I was hoping for a no drill cut rivets and swap type of job, but apparently that wont happen.

I thought for sure the burb and truck frames had the same spacings, etc.
with today's shitty fuels, I was thinking it would be a good idea to have an aux tank of some sort that you can put all the fuel into, then run the fuel through a cheap spin on water seperator/ filter element, then dump it in the main tank. that way, the main tank never gets contaminated as long as you only put fuel in the aux, and have it pumping to the main as you fill up, thus never needing dropped and cleaned again, and the big cheap filter gets changed often, and the spendy hard to change OEM filter gets left alone.