I have a Patriot 40 with an os50sx in the nose. It is bad nose heavy with the 50. If you use a 60 engine you might want to consider shortening the nose some. I tried to add lead to the tail but it was quite a chunk so I just fly it nose heavy. The Patrio will need all the power you can get but it likes high rpms the most. I fly mine with 9X9 and I think the rpms are around the 15+ range. The 49 may be the best engine for this plane.