your dealer should have a ODBII scan tool, you then give them circumference of tyre and revs per Km, and they should be able to recallibrate your speedo
there is about 1 cm difference between US KJ and Aus KJ as far as clearance is concerned,
If there is a little rubbing on the wheel well i could always get the heat gun out
i could always see if any tyre guys would let me do a test fit and see if there is any rubbing issues, (hopefull i know)