Actually, A 1.20 is what's needed to pull this around in a somewhat little more than scale. I'm at 4500 feet altitude here and the air is just a tad thin. This plane weighs in at a full twelve pounds and using the Carl Goldberg 108-3 as a close example [which came in at eleven pounds] I chose to follow it's lead. Using a 16-6 prop you'd be surprised how much runway gets used up before it takes to the air [and that's with 20% flaps] I tried a .90 OS at first with the CG Stinson but it was quite underpowered. I'm not into 3D stunts nor do I "wring " my planes to high stress manouvers. I like to just fly mello and close to scale. Winter is still here with a big storm headed my way so the maiden is a ways off for now. I hope Dick can see the photos of this and then give me an opinion. It is an excellent kit and enjoyed every minute of building it. Seeya, MM