Well, just so you know. That's a 2 gallon tank I have under there and that's about as big as will fit where I put it. Without actually measuring, I'm thinking it's about 14"x8" and about 10" tall. Made a custom top plate for it that has the 4 bolts welded to it to mount to the bed and welded a generic gas tank fill neck to it so it stuck up through the bed far enough. I still need to make it look a little nicer, but have been waiting until I can afford to line-x the bed - keep spending all my money making it go faster