Preheat your oven to 325ºF. Grease and flour 12 cup fluted tube pan. In a medium bowl, stir together the flour, salt, baking powder, and baking soda. In 1 cup measuring cup, mix milk, vanilla, and 4 tablespoons of bourbon. In a large bowl, with mixer at medium speed, beat brown sugar, 1/2 cup of granulated sugar, and butter, increase speed to high and beat until light and creamy, about 5 minutes. Add the eggs, 1 at a time, beating well after each addition. reduce the speed to low; add flour mixture alternately with milk mixture, beginning and ending with flour mixture, scraping bowl occasionally with rubber spatula. Pour batter into prepared pan. Bake for 1 hour 20 minutes or until cake springs back when lightly touched with finger and toothpick inserted in center of cake comes out clean. Cool in pan for 10 minutes. Loosen cake from side and center of pan; remove from pan, place on wire rack over waxed paper. In a small bowl, combine the orange juice, remaining 1/3 cup of granulated sugar, and remaining 2 tablespoons of bourbon, brush the mixture all over warm cake. Cool cake completely. Makes 20 servings.