Question about moving gas tank

[jfshanks]

Remember those old Monte Carlos in the '70s that had the fill tube for the gas tank behind the tag? Flip down the tag and filler up? Anyone know if it is possible to use that type of setup on a 70 Chevy Stepside? I am definitely going to remove the tank from within the cab and install a replacement under the bed. I would like to "hide" the fill tube and gas cap if possible.

Is this a ridiculous idea? or maybe plausible?

Thanks.

Jason