I did the same thing for my students 55 as Mike did, I ran one tank on the ground then A couple of slightly rich flights then gave it A full on tune up.
As to props I can't remember what we ended up with. I have A big tub full of different size props, mostly APCs. I broke it in with whatever OS said but then started looking for the prop that flew the plane the way the pilot liked. When we found that prop we headed over and bought some more just for that engine/plane.
Outstanding engine, I put the AX line right up there in my top two two strokes.