I have a question about the 3 hard lines running down the driver side unibody rails. I can see that 1 is a brake line and 1 is a fuel supply line, but what is the 3rd line? Its cross section is smaller than the fuel line, so about the size of the brake line, but it seems to run to the tank somewhere. Is this the fuel return line? I was looking through the 00 FSM (I have a 97) and it says the fuel return line isn't used since the fuel pressure regulator in the tank drops the excess fuel back in the tank. Is this 3rd hard line on the unibody rail a useless line?