Fuel tank size

[slotard]

I have a '73 C20, 350/350, Camper Special.

From the factory it appears it had dual tanks, both on the passenger side. At one point the rear tank was removed, so it now has one running from a foot and change in front of the wheel well to midway up the passenger door.

How big is the tank? I thought I was down around 10gal and just put in a full 20 before stopping it myself. I'd like to know if the pump is screwed up or if I just have a bigger tank than I thought - I thought it was 18.

[ray_mcavoy]

Most longbed trucks used a 20 gallon tank. And shortbeds used a 16 gallon tank.

The factory dual tank configuration used a 2nd tank of the same size & design mounted on the opposite side.

[slotard]

The truck has a utility bed painted the same color as the cab (blue). It has two filler caps on the passenger side, I had assumed they were both used at some point (as it wouldn't be hard to patch the rear hole when painting). I guess I'll need to poke around and see what's down there.

Even if it has a 20 gallon tank, it would take some pretty crazy luck for me to be able to drive in, fill it with 20, and decide that's enough... I wonder if it was just that dry.

[ray_mcavoy]

The utility bed was probably built to be somewhat universal in terms of the fuel filler cap locations. And it's possible that your truck might have had a Blazer/Suburban style rear tank installed by the upfitter that installed the utility body.

GM lists the tank sizes as "nominal" or "approximate" so you can probably get a bit more than 20 gallons into a "20 gallon" tank.

[jetmech85]

Some after market beds had two fillers on the same side so they would work with Ford trucks.

[Bigstevex4]

The hose or filler probably holds 1/2 gallion.

[Bigstevex4]

I put a new tank in thought it was 20 but at empty takes 15 galions. wonder some times i got a gallion can keep forgeting to run it out and see.