As long as you have a healthy functioning fuel pump, stock is fine. It's fuel volume that is needed with carbureted systems and if you are exceeding what it can supply, you have other issues. If your plumbing is correct, when the engine stops, the fuel flow stops as long as you are right side up. If you are looking for a way to contain your fuel with a positive shut off or for racing regulations it may be needed otherwise I don't see why you would want or need it.