The only real worry, other than performance, is having a prop with too little pitch such that the engine can over-rev. Ideally the prop will allow the engine to turn up to maximum RPM without over-revving. In other words, anything close to the original will work, but if you go with a lower pitched propeller that usually means it needs to have a larger diameter to stay in the same RPM range. With a larger diameter you have to watch clearance issues -- you don't want it striking your trailer if you use one.

You can send an e-mail to our friends at OJ or Acme and ask for recommendations based on your specifc boat and your typical uses. They will be most helpful.