In reference to your short shaft engine with a smaller crankcase and diffrent reed valve set-up. I have been doing tests on several different setups, and this particular set-up is unique, but was manufactured and sold under several different names. If you want to part with this crankshaft and backplate, let me know and I will try and work out a trade. I have a lot of different "STUFF" to include Poulan, Homelite, Ryobi, McCollough, and a lots more of different names. Flathead