Rear Gas Tank - Need Some Pics

[1-PU70]

Im thinking of putting a rear gas tank under the bed where the spare tire goes. What I would like to see are some pics of some installed to see how low the tank hans down. Would it hang lower then the rear bumper or lower then a tow hich or lower then a spare tire. I woul like to use one that holds at least 21 gal. So some pics from the rear to se how they hang down is what Im looking for. Thanks Gary