Meaning put teh fitting in the sump. Not out the top. not facing down, that sucks, but facing sideways or forward or whatever. I put a bulkhead and hose on the inside so it was about centered/flopping with gravity like the fuel should be.
Not sure I'm explaining the sump well enough. Lets say you weld a 4x4x2 deep box on the bottom of your cell. Wherever it fits. Above that, leave the bottom of the tank intact except you saw a 2.5" or so hole above the sump. To make the fuel go into the hole, you put vertical ribs that run from the corner of the tank to the edge of the hole in an X fashion across the tank. when the fuel tries to rush side to side, it follows the rib to the hole/other vertical rib and funnels in the hole. The full height vertical slosh stopping divider plate goes across the top of the hole, splitting it in half. When the fuel hits the end of the "funnel fins" it hits the divider plate and sprays up or goes down. Sump is full. When the fuel is sloshed sideways/forward/backward in the sump, it hits the wall, sprays up into the ceiling only 2" above as the wall doesn't extend up into the main cell. It is captive down in the little sump. Get you down to the last 1/4 gallon or so.
Hard to do in a boughten cell, so you end up with pieces of plastic pipe and what not