1970 commando gas tank hook ups

can anyone tell me where the hook ups go to? there is one for the filler, one for the vent by the gas cap, one in the sending unit, which i beleive would go to the fuel pump. There is one more on the passenger side that i am not sure where it goes. also, is it an egr valve in the intake behind the carb on the drivers side? and what should it be hooked up to?

1970 commando half cab 225 v-6, rochester dualjet thanks.

 

Some had the return line on the sending unit, the fuel pickup was a separate fitting on the tank so you'll want to be sure you have them hooked up right. If the return is connected at the sender the fuel pick up is on the top of the tank. You'll have to trace the lines to the front and see where they go.
No 225's had an EGR valve, got a picture?

 

Mine has the return in the sending unit, if you pull the sending unit you can see the tube for the pickup going to a filter sock at the bottom of the tank.

 

Pic of my tank. The sending unit is not in, the brass nipple is the fuel pickup.