vented gas tanks

[brianrupnow]

I am going to use a gas tank in my roadster pick-up, similar to the one in the picture. My question is this---I know that I need a vented cap that will allow air into the tank so that as the gasoline is burned, I won't pull a vacuum in the tank. The other side of the coin is that as the car sets in the hot sun, gasoline vapours in the tank will expand and have to go somewhere. I cant really have a vent tube in the tank, as there is nowhere for it to go. and I can't just have a vent "hole" because as I drive the car I don't want fuel sloshing out of the tank into the back of my truck.---Does anyone have a solution for this"