M14P
Glad you bought that up cause the old saying of never go over square i.e. 24” / 2400rpm is a load of bollocks!
I have an aircraft powered by an IO540 and at 2000’ 2200 rpm and 26” is a book value, which I like to use as the engine is turning over at a slower rate and not wearing out as quick!
So the long and short is to look at the book, it will tell you what to run!
NAP