I'm looking to do the dual rotor upgrade to my cb550k1. Found this rotor that is marked as a "cb500/cb550" rotor. Looks identical to every cb550 rotor I've seen but it has notches and a slight lip on the back, presumably for the speedo drive. I'm thinking this rotor is actually from some other cb model, gullwing perhaps? If it is indeed for CB550 and I buy this rotor will that save me the trouble of modifying my speedo drive or is there still not enough clearance between the shoulder of the hub and the inner diameter of the rotor?