Bypass vs Deadhead fuel pressure regulator question.

With one inlet and one outlet, I cannot see how it has a built in bypass.
Agree. I ran a dead head system on a 600 h.p. sbc, then switched to a return because everyone said it was better, guess what, no improvement. If u set the deadhead system up right, it will work for a bunch of h.p. Get into hi rpm and bigger h.p., then return system may be the way to go.. The pump should be behind the tank and lower if possible for both systems , unless in tank.