If its a road only truck, or only goes off road on mild trails, leave the skid plate off. They are notorious for collecting crap and causing gas tanks to rot out. You need to be super anal about cleaning them off, which is not easy.
If you do a lot of off roading I would look for a gas tank skid plate off of a CUCV. The one on my M1008 pickup is a flat skid plate that does not wrap up around the sides like the civilian one. Much less accumulation of grime and debris, and much easier to air blow and hose out.