Hey,

The fuel tank's pick-up line goes to the slanted nipple of the GP valve. Then the straight nipple on the valve goes to the carberator. You still need to connect the over-flow line from the fuel tank to the muffler pressure tap. You need to disconnect this line when you fuel from the fueling valve, so when the tank is full, fuel would come out of this over-flow line.

Robart makes a 4-way fueling valve that takes 2 lines from fuel tank, 1 to the carb, and 1 to the muffler pressure tap. Normally, the pick-up is connected to the carb, and the overflow is connected to the muffler pressure tap. To fuel it, you twist the inlet nipple, which re-connect the pick-up to the inlet nipple, and the overflow goes to an outlet nipple, which lets the overflowing fuel flow out.