I'm assembling a Sportsman Aviation Waco .60 and will put an O.S. 90 four stroke in it. I would like to install a pitts muffler but would like to see some detailed 3-views, so I know what I'm dealing with before I order one. I've been to the SlimLine site, but there doesn't seem to be any detailed specs that I can see. Am I making too big a deal out of it? Should I stop sweating it and just order one? What do you all do/suggest?