More on gas tanks

[Richard H.]

The options plate on my 71 C10 says it has heavy suspension and it is a Sport truck, it does not list the two auxiliary tanks under the bed one on each side behind the cab. I have been lurking and looking here and no one has mentioned this set up. Are these factory items and can I get a sending unit for one of them so I can do away with the seat tank?
Thanks, Richard

[WorkinLonghorn]

Those are common,and I'll bet they were dealer add-ons. Mine all still work but the side tanks didn't come with sending units.I've heard that some did,with a switch on the dash to switch between tanks.Someone else should elaborate on this.
If you plan to use those side tanks,you might need to have them serviced,or at least use a large in-line fuel filter.

[72 cheyenne pdx]

My truck has the three tanks. There are 2 switches in my truck. One on the dash for the gas guage and 1 in the floor for switching tanks. In the future, I will be taking the one in the cab out and use the (2) 18 gallon "saddle" tanks in the the bed. I assumed that they all have sending units in them. Maybe they don't. What is the the easiest way to tell?

[WorkinLonghorn]

On mine it was easy;just one little brown wire going under the door sill which comes from the cab tank.No other wires coming out of the side tanks.

[Richard H.]

Originally Posted by cougar

On mine it was easy;just one little brown wire going under the door sill which comes from the cab tank.No other wires coming out of the side tanks.

That's interesting to know, I'll check tomorrow for any wires. The only wires I've seen so far are for the cargo and inside light. If one tank had a sender that would be sweet.