I located an Isuzu tank with rock guard ( I don't have the year) and it's a huge mother and yes the filler is on the right side, however without taking the body off and doing some major manipulating of the frame tube and body brace, that sucker won't work...I found it not only to deep but to thick...I 'm not removing my body at this time, so I passed on it. Ebay has a plastic 18 gallon for $215, but I'm to cheap...so I have scrounged around the junk yard pile of tanks and have come up with on that will work ( yr. & model unknown). I will have to be creative on the filler, but I like a challenge...bend some muffler pipe... I plan on redesigning the rock guard from the Isuzu to protect miy new tank.
Please Note: The rubber on the filler IS NOT Radiator Hose, the parts store sell Good Gas Filler Hose.