fuel tank

I'm having some issues with my fuel gauge. When I fill the tank up, the needle stops before the top of the scale. Then when it goes down towards the reserve (red), indicating almost empty, and I fill it up, I can only put about 7 gallons in there before the tank is full. So... 1) When the...

Will the three e9 fuel tanks cross fit all all versions with respect to mounting in the body? How about fuel pickup/gauge sending unit mounting and filler attachment? Which ones are actually still available? 16111107592 55L 16111110672 70L 16111112233 72L