No I did not. It's a factory 360 car so, if 5/16 was good enough for it new, it's good enough now. A little side note is that pretty much every mechanical fuel pump has a 5/16 hole to allow fuel in, even the ones that have the ability to change the fuel barb size, behind the fuel barb the hole is 5/16 so, unless your running an electric fuel pump where you can decide the size of the line all the way through the fuel system, having a 3/8 line from the tank to a mechanical fuel pump is not really doing anything. Next time ya have a fuel pump with a 3/8 inlet look down inside the inlet, that hole down there is 5/16.
