I'm thinking they are the same. But to answer this definitively one would need to be the design engineer. For all I know the "P" prefix possibly sold as the stand alone over the counter and mine is the package version. Could also signal a change in who manufactured it or a revision of it.
The take I have has to do with the combination of parts used. The "race" combination (coil, resistor, ECU as a team) for higher output likely causes the ECU to heat more so extended run time may take a toll on the ECU life.
