Sift together flour, baking soda and salt; combine 1 cup with dates and walnuts. Set both mixtures aside.
In a large bowl, cream shortening and sugar until light and fluffy. Add eggs, one at a time, beating well after each addition. Add orange zest. Add reserved flour and date mixtures. Stir in buttermilk just until blended.
Spoon into a greased and floured 10-in. tube pan. Bake at 300° for 1-1/2 to 1-3/4 hours or until a toothpick inserted in the center comes out clean.
For syrup, in a small saucepan, heat orange juice and sugar until sugar is dissolved. Let stand for 30 minutes. Cool cake in pan for 10 minutes before removing to a wire rack. Cool 10 minutes more before pouring syrup over cake.