Try a Master Airscrew 3-blade and consider using a Dubro 3-blade ready spinner. They're made for each other. The Dubros fit MAs with no fitting required.

The idea that a 3-blade is less efficient is bad information. It's true, but actually really bad info. A 12-6 two blade isn't as efficient as a 12-7 two blade, so by the same screwed up logic, you shouldn't use 12-6s, probably one of the most used props around.

The only bad thing about 3-blade props is there are so very few of them available. And oh yes, the ignorant advice that you should avoid them.

The recommendations that exist also cause problems. I've used 12x6(3) on my OS61s, 12x8(3) on my OS75s, 14x7(3) on a number of OS91s, and they all matched the engine/airframes really well. The mfg also did not recommend those props for those engines, not even close. Once again, bad info. Engines nowadays are much more powerful than when MA printed that advice.

See the Tiger in the pictures? It and the Skybolt work best with the pictured 3-blades PLUS those props don't cover the planes with grass clippings.