Proper prop for larger motor

"My son installed a '99 20

"My son installed a '99 200hp Merc. DFI on his '79 SeaCraft which previously had an '82 150hp BlackMax. The BlackMax ran best with a 14.5D X 15"P prop and rpm's were fine, just slow and sluggish. Today he ran it for the first time since completing the installation and with a 14"D X 15P" prop and it turned close to 6000 rpm's and the motor was alarming and that was about 3/4 throttle. He ran it around for a while and said it had plenty power and a great hole shot but tomorrow we will run the 14"D X 19"P prop to keep rpm's down to 5500 max. Any one know how to find the correct prop for this configuration? Thanks"

"Doug, Going from a 15" P

"Doug, Going from a 15" Pitch to a 19" pitch prop will likely drop the WOT RPM by about 800, which may be too much. It is a trial and error process, so it would be best if he could borrow some props to try out, before buying them."

"Thanks Chris, I'll check

"Thanks Chris, I'll check with our cous, Oswald Propeller, and see if Brooks has any Mercs in our range. This way we'll know for sure which works best, then we'll list the other two (ebay?)to sell!
Doug"