I built a preliminary 3d model to visualize how the guts of the plane are going to work out. I've got the header running up and over the wing, to a piece of long silicone tubing into a Soundmaster muffler beyond the wing saddle. There's also an option of putting the tank right behind the engine, but that would be a tight fit for the nosegear. I would also lose the "trendiness" of having the tank at the cg. I think I might do an alternative layout with the exhaust running up and into the turtledeck Magic-style. It might make it easier to put some servos over the wing.