3 nipple fuel pump

[Zukeman]

Is there any mechanical people that can answer a stupid question from me. Actually just want someone to verify my thinking. It’s a 55ESL69A Johnson motor. My question is about the 3 nipple fuel pump. I want to verify that the vacuum nipple is the middle nipple?? I call the first nipple the fuel in from tank. I’ve looked at the parts information and I can only assume the line with a spring inside would be the vacuum line which shows it to be the middle nipple. Thanks ahead if someone can help.

[boats.net]

I think the rear nipple connects to crankcase. Pump fuel into the inlet nipple of fuel pump and fuel will come out the outlet nipple to carbs.