Let me take a guess.

I think that those "longer" gear that you installed have accentuated the "P" factor. The descending blade is chomping away and the other is not. Maybe you should shorten the gear back a little. Plus, I think that 109 rudder is pretty small to begin with. I wouldn't change it mind you. But in order to give it half a chance, I would throttle up very gradually.

I generally have my tail wheels cocked out to the left a little so that right rudder is required for straight taxi. It sort of gives me the jump on things as I throttle up.