Bob T. Try a mezlik 22-8 for 50cc and a mezlik 22-10 for g-62 size. Diff with Carbon fiber should put nut on tight. Ater 1st flight retighten, like a 1/16 of turn usually as very little compression compared to wood. Should be good after that, but check tightness every flying session. I also try to use a lock nut on all my gas engines. If you nose over on rollout, a CF prop will likely survive.
Your wood Xoar's need to be rebalanced if tips are chewed up. That will easily knock of a few RPM.
Most in our club with warbirds use mainly Xoar and mezlik. Even the new Mossi twin by my friend Steve.