[bobcowan]

Do not confuse volume with pressure. Volume is dependent on the fuel pump and lines. Pressure is dependent on the the pressure regulator.

Carburetors generally need about 5-7 PSI. Webers generally need about 3 psi. And EFI generally needs about 55-60 psi.

A 427 needs a reasonable flow, like 255 lph or so. Racing at 7,000 rpm will need a bit more. FI will also need a bit more. Doesn't matter if it has 1 carb or 4, it needs about that much fuel. If you're planning on e-85, it will need about 25% more than that. There are a number of web sites available that will help you calculate the fuel requirements.