If you want to have a pressure regulator which has a return going back to the tank, you can install a '54-'59 sending unit which draws fuel from the top of the tank (instead of from the bottom of the tank). I prefer the '54-59' sending unit because it has a sock on the end of the fuel pickup tube as opposed to the original bottom fuel feed setup which is easily clogged with debris settling in the bottom of the tank.
You can then use the fuel bung at the bottom of the tank for your return line.
