They quit making the 1.2 and started making a 1.35 using the same case. The 1.2 has a lot of power and should be a very good motor for an 8.5lb plane. I have one I am getting ready to put in a Lanier 1/4 Laser 200. The outcome should be the same as what you are doing. These engines need proper ventalation if you put it in a cowled enviroment. I had mine in a MW Stearman and it would overheat. Though I was using a dummy raidial in front of it with a cut out for the engine.