Nagnag is only 64^ but her babies, who she will call to help her, are 64vv heroic encounters. Take some help, or kill them first.
There is NOT a wall that you can run and jump on near Nagnag (to make the mobs from the hall drop off you as you can in Treasury of Claw on the Isle of Desolation so either kill as you move toward her room or expect a lot of mobs on you once you reach her room.
The icon for Grandaddy Strifewing on the current map (as of 05/09/2010) is in the incorrect location, he is actually on the opposite (West) side of the room from where he is indicated (East side) as being.
Enter the Strifewind Isle, Treasury of Claw ( -59, -7, -552 ) /waypoint -59, -7, -552. Head east and kill Nagnag Strifewing (64^) to open the doorway to the room next door. (Newly opened doorway is back out in the main hallway.) Climb up the wall and kill Granddaddy Strifewing (64^) in one of the four rooms, for example, ( -170, 111, 3 ) /waypoint -169.61, 110.89, 3.05 and then pick up the bot.