I am planning on using williams 5 in. wheels plus thinner landing gear. I have altered the rudder to extend it 4 in. without adding more weight. Have drilled out the airlons also. Will lighten the fusalage by building a frame using 1/4 square, & just use the light ply for the saddle & rear ply for the tail feathers. Am using a homie 33cc chainsaw engine with a #28 carb. I noticed that yout engine is mounted head up. I have allways inverted mine. Any advantage to your way?