Interchangeability: The carrier flanges are interchangeable. An OEM flange can be used with an aftermarket quick-change sprocket & sprocket carrier. An aftermarket flange can be used with an OEM sprocket/sprocket carrier (OEM sprocket/sprocket carrier is a single component). There aren't any compatibility issues with respect to the flange. Quick-change sprocket carrier design, however, will differ from one manufacturer to the next. Therefore, a quick-change sprocket from one manufacturer may not mount on a sprocket carrier from another manufacturer. Cush drive pins, OEM or aftermarket, are interchangeable. Chain & sprockets... if you're running a 520 chain, then you need 520 sprockets, likewise for the 525... 520 and 525 share the same pitch, but the inner width/pin length differs between the chains, as does the thickness of the sprockets.