On the 777200ER and 747-400 it is 38-40 inches in a normal style seat. the 744 has slightly wider seats than usual, configured 2-3 upstairs and 2-gap-2 downstairs. The 777-200ER seats are 3-3-3 just like Economy class.
The seats to which you are referring are presumably the "SpaceSeat" on the 777-300ER. The airline has had a policy of being deliberately avoidant of that question, stating that the seats are angled and that therefore no number is meaningful.
But the accountants initially had it in far too dense a configuration, as our colleague Kaiarahi noted on a terrible early flight. It turned out that the initial pitch was just 34 inches, which was the same as 744 Economy on Air New Zealand.
The airline then removed a row of seating, and now has a class-leading product which has pitch of 38 inches (side) and 40 inches (middle).