Another ELECTRIC FUEL PUMP help thread. Kill me now.
I would 100% run a return style regulator. As mentioned above by RRR it keeps the pump cooler, and keeps the fuel from cavitation.
Another thing to consider with a stock tank, is that a rotor/vane style pump is not Optimal for pulling fuel UP and out of a fuel tank. Between that statement, and the 10 guys who will jump on here and tell you "no return is fine" you're on the verge of a holy war of opinions.
just remember there is a right way to do it, and a way that some make it work.