Some tips from the get go. The plane will come out tail heavy with an OS 160. Dont know what your going to use but I am thinking of selling my 160 and buying a RCS 180 gasser. The cowl is too short. I plan on adding about a 1/2" to the length of the cowl. This is the reason the plane is tail heavy. The firebox has to be cut off , all but about 1" of it that is to accomodate propshaft length. adding some fiberglass or looking for a new cowl would allow you to push the engine out further and balance the airplane better. THE GEAR IS WAY TOO SHORT. an 18-6 prop will only have about 1.5" prop clearance even with a 1/4" spacer under the gear. The small cowl also makes my 160 overheat when in a harrier. You might want to consider a baffle in the cowl (my next mod) if your going to use a side mount motor.It's a good flyer but a few fixes could make it a great flyer