Mix together the cake mix, pudding, sour cream, eggs and oil. Using an electric mixer beat the batter for 8 to 10 minutes. Grease and flour a 10 inch tube pan. Pour 1/4 of the batter into pan and sprinkle 1/2 the chocolate chip and walnuts over it. Pour in remaining batter and top with remaining chips and nuts. Bake at 350 degrees for 50 to 60 minutes. Cool for about 10 minutes and then turn out onto a serving plate and cool completely.
