RE: 40 size 3d planes...which do you prefer? 2 or 4 stroke
14x6 is too much for the 55AX.
The 55AX best prop is 13x4 Xoar wood or APC sport (not W).
The 55AX should be enough with the right prop.
If you switch over to a Saito 82, the prop for the 82 is a 14x6 Xoar or Master Airscrew S2 (MAS S2).