A 22B or a 23A are both good breakin props.

The 7400 is lou55, on a 23a, and there was a 7900 on a pt carbon. I had a xoar and was getting 6950 after a gallon with a J-tec pitts muffler. I'm back to the stock muffler and on a JXF 22x8. Its been to cold here to run it again or fly for that matter. So I don't know the new RPM's but as soon as I can run it I'll let ya know.