Floyd it will over fuel, you may feel it choking up, if in flowing more into the same pressure the orifice diameter in the reg is insufficient to cope with the fuel flow then the pressure will increase in the rails, this will then force more through the injectors as the pressure drop across them has increased. In practice the std reg is fine if remapping, if not then expect the car to run richer, on closed loop the ecu has enough lattitude to adjust.
bob
bob