Iv'e a thought. I do not run a spare tire in the back carrier. Mainly due to it wasn't there when I bought the truck and the dual exhaust is now in the way. My exhaust system need to be replaced now as it's old and broken. So... I can use that space for a fuel tank. Building a fuel tank is simple but I just got to thinking about it and how would you pump the fuel? I'm thinking another stock pump connected in line with the original. Add one way check valves if needed. Now if I power each pump off a two way toggle switch I can turn on one or the other as needed. Simple. Fill both tanks. Switch on secondary and run till dry then flip the switch to main and continue on with the benefit of having a gauge till it's time to fill again. Any ideas?