71 Gas tank question

[DocMel]

I have 2 nipples on the fuel sender unit.  One is for fuel to the fuel pump:   Whats the other nipple for

Also, whats the nipple on the passeneger side of the gas tank that sits up high?

[ShelbyDogg]

!/4 return line from the fuel/vapor separator that 440s and Hemis used.  Cap it off or get the 1/4" return line and use it to prevent vapor lock.  The other nipples on the top is for expansion too. You only have one and not 4?

[Alaskan_TA]

1971 gas tank diagram here;

http://www.hamtramck-historical.com/ServiceHighlights/_1971PassengerCarHighlights-02.shtml?load_img=22