Raideron,
The Twist will prop hang easily on the OS .46 with the prop I use, however I can only hold a hover for about 10 seconds (my fault not the plane). I have it slightly tail heavy too. It will pull out of a hover vertical and climb nearly out of sight. Take off roll is only about 30 feet and that is off grass. I don't think the OS .61 will fit in the nose without some modifications. That is a whole lot of engine for that plane. An OS .50 would probably be OK but I would hesitate before putting a bigger two stroke than that on it. Some people are using Saito 72 and 82 four strokes on them but from what I have read the throttle arm is a pain.

WCB