super cub
Are you planning to fly off wheels or floats? Is it a clipped wing or full? Your engine size will depend on you alttitude and the above combinations - my suggestion would be to try it and see - just be careful not to push it to steep for the maiden and see how it performs at a good hieght - my guess is it will fly it but it won't be a power house , but then cubs are at their best when flown scale. Your CG should be right on the main spar of the wing - I would balance at the rear of the spar to start. As far as the engine mount judge by other holes depending on your motor mount holes (it is difficult without the plans) you may want to sek a more experienced builder out near you who can advise you on this but in my experience if it's close it will work. good luck and hope this helps.