Alot of times the fuselage sides, in this case the cheeks forward of the firewall need to be trimmed/adjusted on the side of the muffler for clearance. The easiest way is take a dremel and just grind it accodingly for good clearance. Just make sure the thrustlines are within what the plan calls for, then trim the rest for good fit.


Most of the time you won't ever notice after the engine/muffler is installed. Good luck.