When I first got my 49 the PO had done something similar to what you are talking about. In my case they didn't do a very good job of it. They basically took the tank out of the cab, turned it around and bolted it to the front bed panel. After that they took a piece of 1/8" thick sheet metal and welded that between the bed sides to protect the tank from stuff in the bed.
It can be done and done well. I've seen several trucks at truck shows that have built in boxes in the bed that combine storage and fuel tanks.

 

Its pretty much a safety thing all around. It just seems dangerous to have gas in the cab with you. It seems to me that in a roll over or a "T-bone" hit from the side you could be trapped inside with all that fuel and fire.

 

Logically that may seem to be true and it is if you have a weak or leaky tank. But cobbling something up in the rear of the truck from parts that were never designed for it can be even more dangerous in a rear end crash.

This video is not of a pickup but it is in Russia where the crash standards for automakers have been almost non-existent. http://www.liveleak.com/view?i=e22_1347381858

So if you relocate the tank to the rear I would make sure that there is nothing around it, like a bolt or non-reinforced trailer hitch that could penetrate the tank in a crash. And if you are using a plastic tank you might want to think about installing some sort of shield. Here is what happens when the design is inadequate: Gas Tank Explosions - Crown Victoria Police Car Explosions

If you do move the tank to the rear I would also make sure that you have a stout rear bumper which leave out those that want to go bumper-less.

Since rear end collisions are the most common type of accident (see second paragraph) you might want to put some extra thought into gas tank relocation. You could be making things worse.

 

Hey Pete,
All the manufacturers took the tank out of the passenger compartment - not a vote of confidence for keeping it in there. I definitely agree that you need to put some support around the tank if it goes in back. Our truck's gas tank support in pic.

Ben in Austin
1950 F1

 

That is true Ben and I'm not suggesting otherwise, it is just that I think that very few of us test our work the way that manufacturers are require to do. I'm not sure what I am looking at in your picture but I am guessing that you are building a load floor support system with a plastic (?) tank in the rear of your '50 F-1? It looks pretty stout on top but what about underneath? If you get hit in the rear the chances are that you are in traffic and are on your own brakes which raises the rear of your truck. And the chances if you are hit in the rear it will be by a passenger car with a lower front end and he will be on his brakes which lowers his front end even more resulting in a crash where he "submarines" your truck. If you don't have equally stout protection underneath you could have a problem.

I'm not being critical of your design as I'm not there looking at it, just pointing out potential pitfalls that we all need to think about. Eventually I would like to move my tank out of my cab but I have to finish all the other work that I started on it first. Little things like getting it to run, steer and stop . . . when and where I want it to go.

 

Hey Pete,
Our's is the 1970 Mustang 22 gallon tank used by quite a few folks on here. We used Jniolin's specs for our install then put in some fairly serious support around the tank & it's inside the frame. That's about as good as we could do it. Still always a risk....

Good luck on your build. If you use this tank don't make the mistake we made - see that nice round spot up on top of the tank in this pic. If you use aftermarket gauges you need to stick an aftermarket sender in there - our Christmas project now since I overlooked that the first go round. Grr...

Ben in Austin
1950 F1

 

That fits pretty nicely Ben. Thanks for the info. I can see the tank better in that last picture and I see that it is metal which is good but I still would put a shield under it. 16 gauge should do the trick. Some of the OEMs even use a plastic shield. I have seen SAE arguments for the plastic being tougher than the metal. Maybe so in some specific tests but in case there is a fire the metal tank should give you some extra time to get out of the way.

Thanks again for the pix.