Sift together 2 cups plain flour, 1/4 cup sugar and 1/2 teaspoon salt. Add 1 cup soft butter and 2 teaspoons vanilla. Work with large spoon or hands until well blended. Add 2 cups finely chopped pecans and mix well. Shape in 1 inch balls. Roll in 1 cup finely chopped pecans. Bake on ungreased cookie sheet in 325 degree oven about 25 minutes.