mike star...best point of view yet!...really it is something to think about!

I had a 1991 17ft Glastron with the 4.3LX (4-barrel) 180hp motor. Somewhat like your boat. The best all around prop for that boat was a 21" QSS Mercury Quicksilver prop. It turned 4800-5000 RPM at 57mph (on GPS). A Mirage Plus 21" might be a good choice too. It might be a little more expensive though.

I think I would try the Mirage Plus 21.

I think the Mirage will have too much blade area for that boat, I bet a Laser II would do the job. One of my customers has an 18' Donzi, the Laser was 2-3 MPH faster than the Mirage. See Laser. Probaly stay with the same pitch. Don't hold it against me, but I am biased towards Merc props.

Keep the same pitch in SS. Try it out, record all the important facts like rpm, speed and holeshot. Call a good prop guy and get it blueprinted to your requirements.

Would you recommend a 3 or 4 blade?

Let me throw in my .02, just remember free advice is worth every penny. I think the boat, due to its size, will be happier with a three blade. I agree that the Mirage may have too much blade area. Remeber, most of us are dealing with larger, heavier boats. In short, I agree with audacity (worries me a little:D). A mercury laser or a Turbo would probably be a good place to start. Probably 24" for the turbo would work. I have a 22" Turbo kicking around somewhere but I suspect that it will be a little too small (in pitch) for you. While it is true that stock stainless props are much stronger than aluminum and therefore won't break as easily to protect your drive, a rubber hub will provide a degree of protection. If you can stay off the rocks, you will find that floating debris such as small branches that would bend the blades on your aluminum prop will be sliced up and spit out with no damage to your stainless prop. I spent 8 years boating on my local river with stainless props and ran over countless branches with no ill effects. Hope this is useful.

Mirage is a three blade prop, but I think Mbam and Laster are right, it may have more blade area than you need.

Don't kill the messanger -

I emailed 4 winns my question and they said to stay with the same pitch and diameter and keep the 3 blades.

I guess I will just have to buy another boat since there are conflicting view!!!!!!!!!!!;) ;) ;)

Watch out with the Laser II (23"). I tried one on my Glastron that I mentioned earlier in this thread. That prop would ventilate alot on turns. I think it was meant for large outboards. That's what the dealer I borrowed the prop from told me.