That's a good question, and a little more to think about. On an EFI system the fuel is delivered under pressure by the pump in the tank, so frictional loss isn't that big of a deal for such a short distance. On a vacuum pump, (mechanical) friction loss on even a short distance is possible, the longer the lift, the lower the delivery output, so a larger suction line COULD help. As I DON"T do carbs , I will say,,,,maybe