I have 1971 cutla supreme. Thye gas tank was taken out and it ws rusted.
There was four lines attached to it. two line from each side of the tank, and one large diameter line from the middle and also the return unit which has one line.
All those line are connected together at the top of the gas tank to the body behind the back seat with a bracket. No idea where those lines are going.
The fuel tank has a barcket t0 connect all those line including the fuel line form the return unit.
cant see any line anywhere to the engine .
Now I am going to but a new tank with a new return unit whai has two lines to it one will be the main fuel line and the other is the return line. No idea how to cennect the rest and where do they go. Please help

 

It's been to long since I took my tank out, but the fuel and return run down the inside of the passenger frame rail on my 71 vert. I think the other two go to a "vapor-liquid separator" but IDK for sure. Can't help more than that.

 

Welcome! The outer two on the gas tank are the vents. They lead to the can in the back seat. The large tube from the can in the seat goes to the center tube on the gas tank. Then Depending on your fuel pump (if it has a return line equipped or not) will depend on what fuel sending unit you get.(one or two lines) Larger is fuel delivery smaller is the return line. There is a great pic in the service manual of this, I'm sure someone will come along and post one for ya. Best thing you can do first is get the manual.