I have gone off on a tangent here. I will be making the plane a taildragger so I have eliminated the nose wheel assembly on the firewall. I had to move the firewall aft about 3/4 of an inch to accomodate the OS .61 with the rear needle valve assembly. This might give me some grief later on with respect to the c/g. The muffler on this engine is large and very effective. Here you see the 1/2 inch angled balsa and the formers in preparation to be glued.