I asked this question in the context of wanting to know when it was okay to lean the mixture, given that, as I understand it, you're not meant to do so with power greater than 75% with the O-360.
I've just checked the POH which states that with a 76.58 prop at sea level, 2700rpm gives a power output of 70%. At higher altitudes, this value decreases as expected. I normally cruise at 2400-2500rpm so I guess I can lean the mixture at will?