The axle bolt on the right is only 1/16th" from the top muffler or I could screw the shocks down tighter. Short Shots would give it some more space but I hate their sound.
Sorry Jim, somewhere I got the idea you needed a Pitts for an OS 70 to 90. The Turbo Header is my choice for a compact flexible exhaust.
Pete, I think the new Graupner G-Sonic props are very APC like. I received two yesterday for the OS 56 Aplha and for a Saito 56.
With my 13.5" shocks I have no trouble scrubbing my tires edge to edge.