Yes he could. But the problem with the tach or whatever problem the boat has is not solved with that.

I have a 21p M+ that I'm trying to get rid of! will let go for $200 plus the ride...

It got my 25OL up pretty well, but you may look at a 21 rev4! That prop threw my boat up at 3k rpms no tabs and walked right up at 2500 no tabs. Full fuel but just me. (454mag)

the rev 4 is a great prop for deep drives ,it sounds like you might have b1 with the 1.68 gears instead of 1.50 which gave less powered boats a better prop choice. the other gears are the 1.36 which is for higher hp boats. tach sounds off, I had a merc 502 390hp at the prop and would turn it 4800 with a ol 24. see if theres a gear # on the side of the drive and have the tach checked your slip should be between 12 to 15% . good luck