This is my reply from dodge charger.com That's the correct (i.e. factory-correct) configuration, strange as it may seem. I've used 5/16" rubber fuel line before and just slowly worked it onto the sending unit's 3/8" stub. It ain't easy...

If you're restoring the car, a swap to 3/8" fuel line up to the fuel pump is a pretty common and fairly inexpensive change to make. The return lines are 1/4" regardless.