First I'd strongly urge you to get the pitch
and diameter from the original prop.
When trying to sort out the prop for Boracay I went through every table and chart that I could think of, had the prop repitched then had the diameter reduced and I'm still 200 rpm
short of desirable.
For the record
I'm running a 2:1 ZF63, John Deere 4045D (85 hp at 2500rpm) with an estimated boat weight of 15 tonne and a LWL of about 33'. The propeller
is down to 21 D x 13.293 P.
They wanted to sell me a new prop of about 22 x 12, but the cash don't flow like it used to!
As far as I know the shop didn't even look at the tables. They looked at the original prop and my rpm figures and went from there.
It can take years (and several propellers) to get the prop right on a heavy cruising yacht.