something to think about : running the fuel from the tank through pump & filters , through the rails, then the regulator and then returning to the tank puts heat into the fuel. For a drag car, this may not matter much. for a street car or non drag race car, this could be an issue as the fuel will get hotter and hotter during use. I'm going to be changing from that set up to one that pumps to the regulator with a return and a deadhead feed to the rails. I've got a gauge at the rail and also a sending unit to the ECU to monitor rail pressure.