Hi; I have a Bushmaster. Did not build it, but was around helping a bit, at the time it came together. Owner, and builder passed away, after it sat unused for the better part of 20 years. He built two of them, and essentially did not fly either of them enough to work out the bugs, or learn the capabilities. Both aircraft were sold, after the builders passing. Mine was done, at a time that Milo DeAngeles(?spelling) in B.C. Canada, was a source of info, parts, and was comrade of the builder. This part of Idaho, is not far from B.C. Thus it was known originally as a Canadian Bushmaster. Mine has cub airfoil, new one piece, full length spars, with wings one bay longer on each side, than the longer wing Super Cubs. Both the flaps, and ailerons are of similiar lenth, that being roughly 90 some inches each. The second aircraft he built, was done with D and E wings, so I have a little knowledge of both. My Bushmaster, started life, with a ford 3.8L V6, liquid cooled on it. It was kind of a nose heavy pig equiped with that engine. I flew it 140 hours that way. Subsequently, I put an 0-360 Lyc, with constant speed prop, on it and it acts a little more like a Super Cub now, but is a heavier, like 200 pounds. It does not stall quite as slow, nor take off quite as short. There are a number of these " types" around, with variations of engines, and differences in fuselage lengthening processes. Dave Blanton instructed a different process for the Ford-Javelin, which I believe resulted in tail feathers being in the same plane on the lengthened version, as they were on the PA20, or 22. Some of the guys are moving the horizontal surfaces, such that they mimic the Supercub tail positioning geometry which as I have flown the different versions, it strikes me as the way to do it. The one significant difference in these conversions, in my opinion, is the difference in the wing Angle of Incidence, compared to the Supercub. This difference, if not modified from the original 20 and 22 fuselages, results in an aircraft that is faster in cruse, and with a bit less performance in take off and landing as compared to the cub. It would be hard to assess a specific airframe modificaton without measuring it very carfully, and flying it. The differing weights and power plants, have produced aircraft that appear to have significantly different characteristics. Experimental it is called apparently for good reason. I doubt that any two are going to fly the same, other than possibly those done by one person, and exactly to consistent STC specifications. It is my opinion, that with guys all over everywhere, whacking off fuselage, and then lenthening them between 18 and 36 inches, and welding back together, has produced some significant differences in performance characteristics. As an aside, I have always wanted to assemble another fuselage, with a few improvements, and hang an 0-540 on it. I might do it, and suspect that when finished, I would wonder why, because I suspect that the lessons learned, would be the added weight, hanging off the front of a fuselage originally built for 0-235 thru 0-320's and what a person would have to do to get it in balance, would reduce performance in most situations, that the gains of additional power, would more than likely be mostly offset by more weight, and fuel consumption. If it was cheap and easy, I'd really like to try it, and think probably when it was compared to the Lyc.0-360 version I have now, the results would be mostly disappointment. Lighter, with more power, would be ideal. Usually the two, don't go together. I know this will sound stupid, but I am convinced that in cruise, the Bushmaster, with the large engine, would go too fast for comfort. Those big wings, really beat you up, in even light turbulence, when you get going 125 to 140mph. I run my 0-360, throttled way back, to keep it around 115. Who ever heard of an airplane that goes too fast? Is that possible? Sure is for me. A lot of opinions, not much factually useful.