RE: .60 engine in a .40 plane ?
If it is anything like the last .40 size Stik ARF that I bought, it may just NEED the extra weight of a .60 to not be tail heavy. Prop ground clearance may be an issue, especially if it's a trike. Stik taildraggers are so docile that you really have to have taildragger phobia to build them as trikes.