I have built three of the voyagers and rebuilt two of them several times before replacing them. This (the third one ), is the only one I have installed an inverted engine in. The other two ( and rebuilds) I mounted the engine upright and turned the throttle around 180 degrees to the other side to match the push rod. However it is not hard to do to move the push rod to the other side if you want to do that. Just drill you some new holes for the push rod tubing and glue it in place where you need it. Be careful and remove the tank before drilling. Be sure to spray the inside of the cowling with clear epoxy spray paint. That will fuel proof it with our adding very much weight. Never moved the servo or changed out any hardware from the original in the box. Have to say all my crashes were the result of trying to do things with it that was not intended for that plane. Including flying inverted between trees and branches that were close to the ground.