What the heck is 11/8? 45/45 I understand to be campy integrated. Campy integrated headsets have at least 2 different stack heights based on changing the top cap, one is approx 10-15mm and the other is much less.

Maximum spacers + stem is dependent on your fork manufacturer. For example 3t says 90mm above the headtube, that means INCLUDING the headset top cap, relevant spacers and stem 'height'.