One of the most frequently-asked questions from owners of older Ford pickups is "How do I remove the in-cab fuel tank and install a replacement under the bed?"  Some people simply want to gain some additional storage inside, others want to install sound system equipment, like a subwoofer. And some just simply feel unsafe with the fuel tank inside the cab, wondering about the possible consequences in the event of a serious collision. (To those people I have a response: If you get into a serious enough collision where the cab AND the fuel tank is breached, you're probably not going to be alive to worry about the possibility of fire!)

     However, a valid reason for wanting to relocate the tank involves gas fumes inside the cab. If the filler neck grommet isn't completely sealed against the cab wall, any drippage when refueling will seep into the cab, and the fumes make driving the truck unpleasant. This problem can be solved by replacing the fuel filler neck grommet and fuel cap, to ensure proper sealing.

     However, if you're set on removing the in-cab tank, for whatever reason, you have several options available. Let's first take a moment and review the various styles of optional fuel tanks available either from the factory or installed by the local Ford dealer.

     The easiest by far is to find a '67-'72 Ford pickup equipped with the Camper Special (CS) option...though they were an available option on all trucks, so don't limit your salvage-yard search. Most of these trucks came with an auxiliary fuel tank which was mounted between the frame rails under the cab and bed. These tanks are filled from the side, with '67-'69 trucks having a filler neck located above the beltline, while the '70-'72 trucks have the filler neck below the beltline.  If you're fortunate enough to find a CS in a salvage yard, be sure to grab all the hardware, including the tank, filler neck, lines, cross-frame bracket, fuel tank straps, skid plate and in-bed fuel filler neck cover (Fig. 1).  Installing this tank will require cutting a hole in the side of the bed and another hole in the bed floor to install the filler neck.

Fig. 2 - The in-bed fuel filler neck
cover on '70-'72 models.

Fig. 3 - This is the hole cut into the pickup bed's floor to accommodate  a factory auxiliary fuel tank filler neck. (Click to enlarge)

Fig. 4 - On the left is the factory auxiliary fuel filler neck location on '67-'69 pickups. The '70-'72 trucks had the filler neck located below the beltline (pictured on the right).

     Just for the visual, here are some shots of the above style of factory auxiliary tank taken as I was doing a mock installation on my '67 prior to getting the pieces cleaned up and painted. You can see that width of the tank will interfere with the installation of a dual-exhaust system, requiring both pipes to run down the passenger side. (As I get the the tank and hardware cleaned and painted, I'll replace the pictures on this page.) These tanks will work on either longbed or shortbed trucks and hold 25 gallons of fuel.

Fig. 11

Fig. 12

     Here is one variety of a truck equipped with dealer-installed steel auxiliary tanks. If equipped with a single tank, such as on Camper Specials with the built-in toolbox in the side of the bed, the tank will be mounted on the driver's side. Trucks without the built-in toolbox might have dual tanks. This style can be easily spotted by their lightweight aluminum doors mounted on the fender exterior.

     These tanks hang from the bottom of the bed outside the frame with long bolts and retaining straps. They are not equipped with sending units, so they are unsuitable for use as primary tanks without some additional work to add one. Fig. 13 (above) shows one of these styles being removed from a '72 Camper Special. The wooden slat on the ground beside the tank is one of several used as insulators between the tank and the bed. You can also see the notch towards the rear of this tank which is necessary to clear the leaf spring mounting bracket.

     Here's another example of some dealer-installed auxiliary tanks, also commonly know as 'saddle tanks'. These plastic tanks have no visible filler on the outside of the truck because each tank's filler neck is located inside the rear wheelwell. (I'm not sure if these are equipped with sending units....I'll check into it.)

     Another factory option for an auxiliary fuel tank which can be used as a bolt-on for the '67-'72 era of Ford pickups actually was an option during the '73-'79 era. Because the rear frame rails (from the rear of the cab on back) on the '73-'79 2WD trucks are 4" wider than the previous generation, the standard rear-mounted fuel tanks cannot be used. However, the '73-'77-1/2 4WD truck's frames were NOT wider....they are the same width as the '67-'72 generation and will fit the earlier trucks perfectly. These highboys still used the in-cab tank, but a plastic 20-gallon auxiliary tank was available which fit between the rear frame rails. It was filled from the side, so an access door would have to be fabricated on the bed side for refueling (see Fig. 17).

Fig. 18 - This plastic auxiliary fuel tank measures approximately 27" x 17" x 15".