Fuel Injection vs. Webers, what's the difference in plumbing/hardware between the 2 Options

[Type 47]

OK, i get carbs only need one fuel line, but hey, there are 2 sticking out of the bottom of the tank.

I Did the Tangerine SS lines to eventually go back to FI, but going with the Webers to get the thing up and running.

Out of the tunnel and into engine bay, what's going on with the orphan fuel line? Block it off out of the tank or in the engine bay? Which one gets blocked off? The one with the tank screen filter or the other?

And What the Hell is this little white tube? Is it for the FI or does it have some function with the carbs? I don't think so but I keep seeing this tube in my disassembly pics.

[Robarabian]

The one with the filter is the supply line. Do not block it off. Even with carbs you can and should run the return line. Weber makes a fitting for the dual carb setup that is a "T" banjo. You plumb supply to one side of it and run the other side to the return line. That way the fuel is being cooled and you wont vapor lock.

I assume you know you cant use the stock fuel pump, you need 3-5 psi, not 60.

IF you're not running the return line, then yes, you can cap it at the tank, not the line end, which would be real dangerous.

[BK911]

The one with the filter is the supply line. Do not block it off. Even with carbs you can and should run the return line. Weber makes a fitting for the dual carb setup that is a "T" banjo. You plumb supply to one side of it and run the other side to the return line. That way the fuel is being cooled and you wont vapor lock.

I assume you know you cant use the stock fuel pump, you need 3-5 psi, not 60.

IF you're not running the return line, then yes, you can cap it at the tank, not the line end, which would be real dangerous.

Just for clarification...
The pump does not produce 60 psi unless the system is designed that way.
With a supply and return line, the pump will not make anywhere 60 unless there are restrictions somewhere in the line.
The PMO fuel regulator is perfect for converting from FI to carbs.
With a stock pump, adjust the return pressure drop until the pressure hits ~4 psi.