I have one, the 35cc Red Head Gasser with the same muffler, but I think mine is newer, and that Carb is different than mine, is that the 26cc engine ?
the 35cc is a strong engine, it will turn a Zinger 20X8 over 7600, and a 3W 20X8 at 7250 tuned for flight, and pull a heavy 15 pound, 82" span GeeBee Y straight up rather well, an acrobatic plane of this size should be a pond lighter than my GeeBee was, a 21X6 or 5 would be better for a big Cub or some other high wing,

Jim