Not sure if this is the right place or not, if not mods please move as needed. Found this online: http://attatank.com/atta/freedom_fill.html Sorry about the image size, it's their image. I'm going to be picking up my '87 F150 in a couple of weeks. After I get done doing some work on it (fuel system mainly) I'm planning on adding a tool box to the bed. The company above sells toolboxes that have an aux fuel tank under them (along with many other configurations). The truck I'm getting will have 2 19gal tanks, then if I get the 50gal aux tank, that will give me an excellent range for the truck (though driving with an extra 50gal of gas will kill the non-existent MPG for the truck) What are your thoughts on this? good, bad, indifferent or is this just an accident waiting to happen?