I just picked up a fuel tank from a 2001 Neon to put where my spare tire mounts in my 2001 Dakota.
The fuel system looks the same for both vehicles and fuel pressure seem to be the same.
I have the old rusted bed from my truck sitting here to use the fuel door from and a switching valve from a GMC that will work.
Has any one tried this before?
Gas prices here in Ontario are getting a little out of control and I live 5 minutes from border where I can buy gas for a lot cheaper. I can't make it a whole week on one tank so I need to increase my capacity.

 

Not sure if the switching valve from an older truck will work, but if it's off an EFI vehicle, I'm sure it'll be fine. Just remember to cut power to the fuel pump with the changeover action.

 

License plate flip down for filling the extra tank? Just a thought. I know the older fords and chevys had dual tanks. Dodge never did tho. I know on the fords they had what is called a dual function reservoir. Basically both tanks a plumbed into it and when you kill the one pump to turn on the other one it opens the valve and you are now running on the reserve tank.

http://www.supermotors.net/getfile/6.../reservoir.jpg

Btw dont forget to wire in the sending unit or another fuel gauge. I cant tell you how many times my dad flipped the switch in our work ford only 2 find out the second tank was empty lol