I'd like to move mine back there too (1979 W150 short bed standard cab). I guess having someone build one would be pricey. And where would the fill be? I hate to cut the bed side. I had dual tanks, but the plastic under bed one was cracked, so I removed it and since I added dual exhausts there is not room for another there. I'm strictly running off in cab tank now but would like to eliminate that one.