I installed a 16 gal universal gas tank from tanks inc under my 51 on passengers side. I reused the original cab filler tube, rotated 180 degrees to a 2'' filler exhaust tube-pipe. had to cut the little corner truck brace out to get the tank up higher into the frame. the filler is just infront of the rear fender but below the bedwood, filter tube is in-between the frame channel above the frame for easy access & replacement.
http://s67.photobucket.com/albums/h298/1951otter/ you'll have to scroll down the page after you open the link ... forget the logon bit at the top.
http://www.stovebolt.com/bboard/cgi...d=results&record=2453693-100543-4RRS http://www.stovebolt.com/bboard/cgi-bin//ultimatebb.cgi?ubb=get_topic;f=22;t=002404#000006
update::
http://s67.photobucket.com/albums/h298/1951otter/ I finally got hold of a digital camera. sorry no shots of the completed set up as i'm about to haul the 1/2t off to the blaster..... paint soon.
these shots are of my under pass bed gas tank, a 16 gallon w/ the old cab filler turned 180 and welded to a plate. a decorative piece made to cover the bed outside was welded to the original cab filler neck and bolted w/ three 1/4'' bolts. i flared out the stock filler neck at the end to 2''. as was told to me by a friend,... '''jim this is a drive-a-way tank filler, and you'll have the station's hose''' . this mounts to the passenger side, in front of the rear fender, below wood skirting. there is room for a 2'' hose to connect the filler spout to the tank inlet neck.
it a universal steel tank from tanks inc. it's 10''x11''x34''.
http://www.tanksinc.com/index.cfm/p...ry_id=69/home_id=59/mode=prod/prd128.htm the top of the univ. tank filler neck was welded closed. i really do not like the filler in the wood area of the bed. a piece of 2'' muffler pipe was fit & welded to the tank top-edge, side, inline w/ the new hole cut into the bed skirt. the tank comes w/ an anti-roll vent so the rubber hose can be placed above the tank's highest point. i welded shut the original filler neck's vent tube as it was not needed w/ this new tank. i vented mine to inside the fender well & directed it so mud and crud will not plug the hose end. i had to cut out the stock 3104's frame 'corner plate' so the tank would fit as far forward. the four threaded rods are held up to the under side of the bed so the tank is as high as possible. 3/4'' nuts welded to small plates welded to the bed's cross wood braces hold the tank up. i glued rubber strips to the bottom cross braces as well as the top of the tank when fitted so vibration is eliminated. tank finished in Por 15. if you do this you may have to cut the rear tank corner, next to the pumpkin and weld back a plate, the new 12 bolt rear end was fitted @ the same time @ 2-1/2'' back. this is a some-what tight fit length wise and the kits only offset available @ 1-1/2'' offset. i think the 2-1/2'' offset looks A LOT better than the 1-1/2''. that gave me all the room i needed to fit the full 16 gal tank. the gas pick-up fuel is @ the rear along w/ the sender. i set the sender so it should show empty but it has 3-4 gallons left as reserve.