There are those with more intimate knowledge of the engine, but as far as I know, while the exterior of the engine has changed over the years, the internal "numbers" haven't changed. The bore, stroke, timing and port sizes have remained the same. It is the size of the port from the crank case up the side of the engine that is supposed to be responsible for the burp when mounted sideways. If one burps, they all should burp. Bob Arata had one that was mounted upright in what was basically a Flite Streak with flaps and full fuselage, and it would sound like it completely shut off on outside squares! I don't think I have ever experienced it, but I was schooled to run higher pitched props than what was considered normal. Tank placement on a profile should put the pick up even with the center of the bypass port area as a starting place, and that has always worked for me.
Type at you later,
Dan McEntee