Welcome to the site, and squinting at your avatar you may have an Ericson 31C. Perhaps. Your bio needs to be fleshed out, and most important you need a 'sig line' that gives info to quickly help others help you... like the reply from Navman in reply #2.
Do you know the sizing for your present prop? Diameter and pitch? Great that you do know the engine and shaft size; that 's a very good start.
Our hull is different, but considering props, I do have experience with the stock two blade fixed, a two blade feathering, and currently a "sailor" design three blade fixed. All have plusses and minuses. You should mess around with the 'search' function here, with the word 'prop', along with modifiers. There are a herd of good threads. This is one boat bit that is often overdue for optimization, having caused slower motoring for years or decades, as prior owners chose to ignore it.
Gotta say, for max efficiency under sail a folder is always a good bet, but they do have downsides, both in basic fit (gotta have room in front of a rudder for the blades to fold in) and their reverse thrust can be -sometimes, and very design dependent - kind of iffy.
If you have a picture of your boat's underbody when out of the water, this can really accelerate the discussion.
Finally, since this is an inquiry about running gear, I will move it to a forum where it will be seen by more members.