Prepare the Elbow Noodles as directed on container, drain and set aside. Shred 1 and 2/3 block of Cheese in one container. Shred the remaining Cheese in another container. In a stock pot over medium heat, melt the Butter. Once melted, whisk in the Flour. It should form a dough type, once that happens slowly whisk in the Milk. Let this simmer slowly, and continuously whisking so it doesn't burn. The mixture will thicken up. Slowly add a handful of Cheese from the 1 and 2/3 container. Whisking it until it is fully melted, than repeat until you have added that entire container. Add your cooked Elbow Noodles to the Cheese mixture and stir until mixed well. Put this mixture in a bake safe container, smooth out top and add the remaining Cheese evenly to the top. Bake at 350 degrees for 30 to 45 minutes so the top layer of cheese in melted and a slight brown.