auxiliary fuel tank for diesel truck

Many trucks have enough room for an additional tank between the body and frame rails. The problem with this is installing the fill piping and cap assembly. I have done two for customers and they came out very nice. We used crossover hoses so the tanks would remain balanced, Same amount of fuel in each tank). This does require cutting the access hole in the body, we matched it to the original. Most of the cost was in the body work and paint.

The thing is, it isn't necessary to keep the tanks full when not needed for long traveling. I think this option is much safer than a fuel tank in the bed of the truck, and it doesn't take up any bed space.