freaky fuel lines

ok i just put my metal fuel lines back into my 73 truck along the frame rail and there are 3 of them. one goes to the pump, one goes to the tank from the pump, and one goes to a charcoal canister. im really confused because the return line to the tank from the pump was never hooked up when i had the truck. is it supposed to be? is there supposed to be a return line on these old trucks and what is the purpose? does anyone know the reasoning behind that? lol im stumped

Not all fuel pumps are created equal . you may use more than one design fuel pump on that engine. if there is a return on the fuel tank and you want to reattach it more power to you.

well, if i dont have one, does the extra gas it dont need just go to the carb and richen the mixture a little or something?