Adding Aux Fuel Tank - hole cut out?

[grantorinosport]

So my 71 F-250 Camper Special was hit by a drunk driver in February (I was not even at home, got a call from local police the next morning to inform me). The bed was pretty damaged on the corner, and as such I am replacing it. The bed had several other bits of damage and issues anyway, so this will be a good thing.

I found a bed. Good shape, little or no rust. Only problem is that it has the tool box but no fuel filler hole. My truck as the aux (factory) gas tank. Other than the bed not having the fuel filler hole on it, it is otherwise what I need.

Is this a simple matter to just cut a round hole in the new bed that doesn't have it? Or, is there significant modification involved in this endeavor?

Seems simple - that is why I am worried. It can't be that simple!

[hillcountryflt]

Isn't there a fuel cap door and hinge setup to acquire and install. Probably can get that off of your previous bed.

[grantorinosport]

Isn't there a fuel cap door and hinge setup to acquire and install. Probably can get that off of your previous bed.

This is the factory aux fuel tank, so there is no door or anything.

[Calfdemon]

The hole in the outside of the bed is one thing, but you also need to cut the area inside the bed to make room for the fill tube. Then the trucks also had the covers that bolted down inside the bed to protect the fill tube and to cover the area that was cut away. The fill tube bolted to the underside of the bed in the same spot where the bolts went to hold down the cover. So all of that is how it came from the factory. Not sure if you have the stock fill tube, but if you do, you should see where it bolts to the underside of the bed, and you will see where you have to cut the inside of the bed to make it fit.

It is a little bit more involved than just cutting the circle... But not too much work that it can't be done. You just have to measure many times so that you cut in the right spot the first time. If you cut the hole in the wrong spot, then the mounting bracket will not line up with the bed for bolt down purposes.

Here is a look up at the underside of mine where you can see the stock fill tube from my 72 and how it bolts up under the bed. You can also see how the bottom of the bed was cut away by Ford (or the dealer) when they installed these tanks. I converted the fill location because it is feeding a crew cab only aux tank and the fill spot is in a different location. The standard cab aux tanks, both the breather line and the fill line went between the frame and the bed over the top. So ignore my fabricated drop down fill tube.

[grantorinosport]

The hole in the outside of the bed is one thing, but you also need to cut the area inside the bed to make room for the fill tube. Then the trucks also had the covers that bolted down inside the bed to protect the fill tube and to cover the area that was cut away. The fill tube bolted to the underside of the bed in the same spot where the bolts went to hold down the cover. So all of that is how it came from the factory. Not sure if you have the stock fill tube, but if you do, you should see where it bolts to the underside of the bed, and you will see where you have to cut the inside of the bed to make it fit.

It is a little bit more involved than just cutting the circle... But not too much work that it can't be done. You just have to measure many times so that you cut in the right spot the first time. If you cut the hole in the wrong spot, then the mounting bracket will not line up with the bed for bolt down purposes.

Here is a look up at the underside of mine where you can see the stock fill tube from my 72 and how it bolts up under the bed. You can also see how the bottom of the bed was cut away by Ford (or the dealer) when they installed these tanks. I converted the fill location because it is feeding a crew cab only aux tank and the fill spot is in a different location. The standard cab aux tanks, both the breather line and the fill line went between the frame and the bed over the top. So ignore my fabricated drop down fill tube.
[ Image ]

Calfdemon,

That is great information - thank you. To answer your question, yes I do have the original installation. The part of the bed that is munched is rear driver side bed, so the tank/fill area is undamaged and I can use that as a guide (and of course re-use fill tubes, etc). I will also be able to re-use that cover in the bed as well.

I was mostly curious how much cutting/mod needs to be done and if there are any "been there done that" tips and tricks from members that may save me from heartache when I try this.

The new bed is supposed to be in really good shape, so the effort to replace the aux tank assembly is well worth it in my opinion (the tool box is on the new bed, so that is 50% of the battle). It is just that I am not a welder, not really a metal working guy or anything like that, so I would consider myself a definite novice at this task.

Your information was great, and I appreciate the input!

[Calfdemon]

Nothing needs to be welded that I can think of. The only metal work would be cutting, and the only area where you really need to be careful is the hole on the outside of the bed, as that will be seen if you cut farther out than the grommet will cover.

The rest of the cutting, like you said, you can use your old bed as a template and just copy what was already done. The other cutting is not seen as it is covered by the fill tube cover that bolts into the bed. So it really is not that big of a job and easy for a novice to do. Just remember the golden rule, measure twice (or more) so you only have to cut once.

[67mann]

To add to what Rich said...should be able to get a rough measurement off your other box or filler neck and work your way up through the bottom off the box.
If you have the cover like mine.....there should be a little room for error without exact measurement .
http://i267.photobucket.com/albums/ii30 ... 0024-2.jpg
http://i267.photobucket.com/albums/ii30 ... 0022-3.jpg