I recently bought a ´71 XLT Camper Special F250.
It has two fueltanks, and I wonder if the tank in the cab, or the one underneath the bed is the main tank.

 

The one in the cab.

 

Thanks a lot!

 

I have a '68 f250 and the main is the tank in the bed....But my fuel guage did not change tanks when I switched them....Had to run a different wire for the main tank...might be a problem with my wiring

 

1967/72 F100/350: The in-cab tank is the main tank, the 25 gallon auxillary tank was a factory installed option, so most trucks do not have it.

Auxillary tank located on the inside of the left frame rail. 1967/69: The exposed fuel cap is located above the scallop (bumpside) line in front of the left rear wheel.

1970/72: The exposed fuel cap is located below the scallop (bumpside) line in front of the left rear wheel.

1967/72: Inside the bed is a shield that protects the fuel filler tube from possible cargo damage.

Adjacent to the drivers side of the seat is the manually operated fuel tank selector valve, only switches the tanks.

Mounted below the dash to a bracket to the left of the steering column, is the selector switch that only changes the dash fuel gauge from one tank to the other.