Add dual tanks?

[rockin_77]

I have a 1977 GMC high sierra with a 350 that was my grandfathers and im slowy restoring it. Im tired of feeling it up so often. It has a single passanger tank and i would like to add one to the driver side. How would i go about doing this. I work at Oreillys and parts are easy to come by. So far on my list is, Tank, sending unit, selector valve, and selector switch. Is there a how to on doing this? Thank you in advance for the information.

[slammed79]

Im tired of feeling it up so often.

But they love it when you do!!!

Anyway... Dual tanks are cool, have you thought about a Blazer tank swap? On a shortbed you can fit the 26 or 31 gallon tank, on long beds, you can go up to the 40 gal Suburban tank, but I've read that its a tight fit. It'll probably be cheaper and less of a headache to do than wiring and plumbing a second tank. Just my .02

And welcome from AZ.

[K20Wulf]

 have you thought about a Blazer tank swap? On a shortbed you can fit the 26 or 31 gallon tank, on long beds, you can go up to the 40 gal Suburban tank, but I've read that its a tight fit. It'll probably be cheaper and less of a headache to do than wiring and plumbing a second tank. Just my .02

And welcome from AZ.

I'm with you on this, I hate my saddle tanks and want to switch to a large single tank in the rear. To the OP: The wiring/plumbing would be much easier with a single tank in the rear.

[Blazin]

Two tank brackets, two straps, some metal fuel line tubingand a a few inches of rubber fuel line. Just a matter of hanging the tank, running the line across the cab mount crossmember, cutting into the current line and installing the valve. You will need to wire up a switch inside the cab, and run wires for the fuel gage.

[Grim 82]

You will also need a way to fill the tank if you have no fuel door on that side of the box. You can graft one on from a donor truck or get creative.

[rockin_77]

The one rear tank sounds like a good idea. It would add traction as well. I have a long bed sorry about leaving that out. How would i run a filler for the one rear tank?

[slammed79]

You can cut your filler section and move it to the back, or the one I like is a guy ran it behind his drivers side taillight and hinged the assembly.

[1979C20]

You could probably even find a way to put it behind the license plate on a flip down like some camaros

[rockin_77]

Ok i dont know how i missed this. My grandpa had adding an aftermarket back in the early 80s but removed it. I have an ugly door on the driver side that i can use to fill the tank. Also i found a selector valve under the truck. I put 12volts to the wire and it clicked. I dont know if it is good or not. I guess at one point there was a switch in the cab that is no longer there.