"The -400 has triple slotted kruger flap set up, "
Isn't a Krueger a non-slotted flap?
On the 747-400, the 3 (per wing) Inboard LE flaps are well-known as Kruegers. These are non-slotted. The (5) Midspan and (6) Outboard are known as Variable Camber and do have slots (air gaps between the wing and the flap).
Rgds.
Q.