Okay, sorry about the drawings but I'm no Auto-Cad person...
Basically weld in a curved sheet like so (represented in black), with notches on the bottom (the black half moon looking things), so the fuel goes in, and less fuel goes out.
I don't know if the drawing makes sense.
The sheet that you weld in would look like this [imagine equally sized and spaced holes] (possibly with more holes on top)