This is an old thread, so there are occasional members who drop in thinking it's the newer 50cc planes thread. It does read "large revolver". I'm sure there is a thread for the big one, but I've never seen it. I'm not a fan.
I'm sure someone has used the 55ra in the big plane. I think I've seen YouTube videos with it. It's basically the same engine with the exhaust port moved to the rear.