Fuel tank vent

IF YOU THINK there is any chance you will build a "monster" engine or go with EFI I would NOT use 1/4" for return. Use same size as feed or larger for return
I'm sticking with a mechanical pump. A full size 1/4" return would make pressure drop off to the carburetor too much. I plan to stay mild to moderate slant 6, so I'm good. Otherwise, I'd run a return regulator with a hot electric pump. I thought about, but that's not the direction I want to go.