One of the guys at my club (Stallwart) has the yellow H9 .40 T-34. It is a great flying plane. I think the he used Hobbico mechanical retracts (I could be wrong). If I remember he has a Saito .82 with a 3 blade prop. The worst part of his plane was the small wheels that did not like to allow take-offs from wet grass. He corrected that with larger mains. I'm going with the stock retracts first, then may have to start looking for some new ones if those don't work out. I'm planning to drop in a OS .704S with 12X6 2 blasd prop for power. Should be enough. Now I'm looking for good pilot busts (thinking 1/7 to 1/8).