It was designed to fit a particular engine that they never released so whatever engine you want to install you will have to figure it out yourself. I used a DA 50 R I already had and I had to angle the cylinder head so the muffler did not be so close to the cowling. It has less room in the front than the TF GS Mustang so it is more difficult to make any engine fit. I got it done though and it flies great. At 27 lbs. ready to fly my wing loading is 12 ounces less than my TF mustang.