Steve
I have one of the older ARC Ladies, and will say that the YS 120 (an older one from a pattern guy) makes it a great flyer. There were at one time seven Ladies flying at my field and the power plants varied (Ys120{1}, YS140{2}, Webra 120{1}, G-23{1}, Supertigre 2300{1), and Supertigre 90{1}), but the occasional 60 that would visit our county field were showing a lack of aerobatic ability compared to the ones we had.

The terminal speed for the airframe is right at 110MPH and was verified by the 120's on 15% and the 140's on 40% were all within 2MPH on a radar gun

I will say that you need to put something as a filler in the fuse where you glue the horzaontal stab to as the fuse will not flex with that added and that will be a good thing.

THe guys with the 140's put bigger ailerons on thiers and there were no flutter problems at all.

You also want to make yours a two aileron servo plane to be able to get the elevator flap mising that will help with the tumbling moves.

I am still flying mine, one of the others mid aired and the rest were retired/sold for the bigger ARF's.

The Lady is a great windy day flyer and is the best windy flyer I know of for its size.

Well, hope you enjoy your as much as I have mine, take care