58 psi. Aftermarket systems usually use a rising rate pressure regulator so that as you start boosting the fuel flow can increase as well. Helps keep idle and light load driving a lot better than just throwing oversized injectors in. Your tuner would need to dial everything in and make it run right once you get away from stock or mopar stage kits
the stock style system is a static, returnless system. meaning, one pressure (58 psi for stock, 75psi for stage 3(i believe)) and fuel flows from the tank to the engine only.
usually with a full aftermarket fuel system, a return line is run back from the motor to the fuel tank. and the pressure is regulated by a 1:1 rising rate regulator at the engine. this 1:1 means for each psi of boost from the turbo, the fuel pressure should rise 1psi.