I left the wood engine mount on it. I wished I had taken it off though once I was finished. I would think the 120 would be to much for this plane as well, just based on the airframe design. The .90 was perfect (for me). I kept the stock muffler and cut the cowl around it. Not the prettiest plane I have done but everyone that saw it only looked at the awesome color scheme anyway Another thing to watch for is very low propeller clearance with stock landing gear. I kept the original landing gear but landings had to be perfectly executed on short grass to avoid contact.