Be careful - the original poster seems to have a parallel valve IO-360, but my power chart is for an angle valve IO-360. The relationship of power vs MP and RPM is quite different for those two engines.Kevin Horton has one for an IO-360 A1B6, which ought to be pretty close, in his draft POH (fig 5.9).
http://www.kilohotel.com/rv8/POH/POH.pdf