MEL/CDL penalty sometimes requires reduction in PERFORMANCE LIMITED EN ROUTE CLIMB WEIGHT. For instance per CDL item 78-31-2

PW equipped B744Pax)
Fan Thrust Reverser Blocker Doors, if missing requires reduction in En Route Climb weight by 2100lbs and increase in flight planning fuel by 0.53% ). Where can I find this weight to apply the limitation?
Thnx