I'm thinking of putting it in my 31% CA Model Extra which weighs 21lbs with a 4.2 brision. The BME might be a little overkill on power but it still weighs about a 1lb less and I sure would like to get away from the vibes of a single cyl. I don't think balancing will be a problem as I could move batteries and or rudd servos with pull pull. By the way, how is the vibration?