Fuel Pump Question

Hey All,
So, for some reason, unbeknownst to me, I ordered 3/8 fuel line from the tank to the pump. My car is a 73 340 Dart Sport. I really do not want to send it back as I bought new clips, hose kits, etc. for the 3/8 line, and I just do not want to go through the hassle packaging everything up and paying for return shipping. My future plans for the car, after I hit the show circuit for a couple of years, is to 6 pack it so the 3/8 line is good. I have found the correct sending unit that has 3/8 out and 1/4 return, but I want a fuel pump that looks stock but has the 3/8 inlet. Will it matter if it is 5/16 up to the carb? I think I found a Carter that is 3/8 inlet and 5/16 outlet to the carb. Is the 5/16 the correct size line from the factory. I am trying restore this car back to factory looking as much as possible. I know the 3/8 to the pump is not factory and there are a few other things that are not factory as well. However, I am still trying to stay as close in appearance as possible. Any help on where to find a factory looking small block fuel pump with a 3/8 inlet would be appreciated. Thanks.