Creamy 3 Cheese Baked Macaroni and Cheese

16 oz. elbow macaroni, about 3 cups
3 T. margarine
1 1/2 c. milk, divided
2 eggs, beaten
16 oz. 1/2" cubed Velveeta cheese
8 oz. shredded mild cheddar cheese, divided
8 oz. shredded Monterey Jack cheese
1 t. salt
1 t. pepper

Heat oven to 375 degrees. Cook macaroni in large pot of water until tender, but not mushy, about 8-10 minutes. Drain well and pour into large mixing bowl. Melt Velveeta cheese and 3/4 c. milk on low heat, stirring often. Pour melted cheese over pasta and stir. Add margarine, remaining milk, eggs, 1 c. each of shredded cheeses, salt and pepper. Mix well and transfer to sprayed 9x13 dish. Pour remaining cheeses on top. Bake until crust is golden brown and casserole is bubbling, about 25 minutes. Serve hot.