If you filled it too full you float that controls your guage may be stuck up on the top. You can fix this by filling it all the way up and putting in some good injector cleaner that will eat the lacqured fuel off the slide.
Or the other way to fix it is go to monroe this saturday and run flat out down by fairfax at about 3:00 in the afternoon. That beating will probably dislodge it as well.