Depends on the engine of the Q7. Higher powered Q7 have the same calipers as the Cayenne Turbo, the Brembo 18Z.
Lower powered Q7s and Touaregs have smaller calipers with 4 pot, that you can fit 330 mm MB discs.
Cayennes also can have Brembos 17Z that are 6 pot and you can fit with 330 mm MB discs.