electronic fuel pump???

If you run a return line, according to Barry Grant, you should run as big or bigger return line than feed line in a bypass system. I don't recall the exact reason for that though. I think to keep the return line pressure to a minimum. Your pump may last longer too with a bypass style regulator since you're not dead heading the pump with all that pressure. You'd be allowing the pump to operate at a lower pressure when there is little fuel flow to the carb. Another advantage that aeromotive told me was that the bypass regulator will flow a lot better than a dead head regulator and your line pressure will also stay more consistent when opening the throttle up. Just my 2 cents.