Combine flour, salt, baking powder and soda; set aside.
In medium-size mixing bowl, beat together the 2/3-cup sugar, margarine, milk and eggs until light and fluffy. Stir in dry ingredients, mixing until thoroughly combined. Add apples and nuts. Spread evenly in greased 9x5x3-inch loaf pan. Sprinkle mixture of remaining sugar and cinnamon over top of batter.
Bake in 350-degree oven about 55 minutes or until wooden toothpick inserted in center comes out clean. Remove from pan and cool on wire rack.