For those of you debating what set up to use,about three weks ago I had the same problem, what engine to use, I finally ordered the bme 50 from cheif despite a lot of people worrying about vibration. Well here is how it tuned out, I put the bme 50 in using the gp mount adapted the way someone on this site said to do it. the mount works great and also you wont have to build up the firewal to get the 7 inches you need. As far as vibration, I am running the 50 with a mejlik 22-10 15%, after dialing inthe carb I am getting minimal vibes nothing i did not expect as far as power , when I first took the pklane out for its maiden flight a freind of mine wanted to nose it up and see if it was to lean(I guess he has not had much time with gassers) when he did this I throttled up and he was amazed that the plne wanted to go vertical from his hands. After thi it was time to fly. All I can say about this set up is it works for me . Anyone wanting to use this engine, put it in and hold on the vertical will amaze you
Just My two cents