Hi all. I am putting together a 60 size Great Planes Matt Chapman Eagle 580 nitro version airplane and am wondering how the engine needs to be installed in order to use a Pitts slimline muffler setup. I am new to these types of planes. The book calls out to use a OS81FS and shows the engine mounted sideways with the exhaust exiting out the right side of the cowl. I am installing my OS91FS for an engine and was wondering if I can install it inverted. Correct me if I am wrong, but isn't that the only way you can use a Pitts style muffler setup? I tried calling Great Planes tech support today, but they are closed. Any help with this would be greatly apprecited. Thanks...