does it matter if the carbs are off a 1200 gx? its the same thing as stated by dman if your really fanatical about having round tops go find your self a pair of early round tops off a roadster or 1600 change over the jets and linkages there you have your self a "genuine" set of gx carbs no one will pick the difference. but then you cant buy rebuild kits for the round tops so i think i would rather have square tops