883 is currently a 77W every Su, Tu, We, Th, Sa and 74A every Mo & Fr and the schedules will remain that way all the way to end of March. If you want the new biz, I'd suggest you stick (the non z shaped) on the days that it is operated by the 77W. If you go with the days using the 74A, there will be a chance the flight might be swapped with the 744 or 74J which has the old seats. Chances of a 77W on long haul getting swapped with another equipment is smaller than a 74A getting swapped with 744/74J.