...which comes out to 31" - 32" inches. If you were happier with a lower power setting, lower rpm might be more efficient for the prop.  I haven't done the math on that.

At takeoff MP I never run less than 2750rpm because as you lower the rpm you are moving the max intra cylinder pressure closer to top dead center and higher max pressure.

I won't come back (to 2500) on the rpm until the MP is down to 32" or less.

re: the rpm argument, I think it seldom plays in the wear equation.  High pressures break almost everything.   High temps soften cylinders.   Bad torqueing concentrates stress.  Valves break because the guide or the seat is incorrect. Bad metallurgy will fail at any rpm.  Corrosion will destroy a cam.   but how many times does a well-oiled engine fail because it has two many revolutions on a connecting rod journal?   It's been said "It's not how hard you run it, it's how you run it hard."     I haven't seen any convincing evidence to the contrary, although I am definitely not an expert.

For a more definitive treatment, read John Deakin's two series on engine management below in the short term.

If you haven't been to APS yet, you should go.   ...not just to know where to put the knobs.  You will have a much clearer understanding of your engine.

Registration for that is here.   The live course is given occasionally in Ada.  The online course is available immediately.

(No they don't pay me.   It's just that when you ask a question the answer always starts with "Well here's the data on that....."   So nice in a world where the answer is more often "I feel...." or "I think..." or "For decades we have...." or "I'm sorry that question is not listed on my script..." )

http://www.advancedpilot.com/ 

Deakin's series on engine management in general can be found here: (read them in order by "part xx")

His series on running a turbo charged engine is here: 

Colyn