Combine 1 cup each sugar, brown sugar and light corn syrup. Slowly bring to a hard boil. Add 2 sticks butter; when melted, slowly add 1 (6 ounce) can milk. Cook to firm ball stage, 244-248 degrees. (Remember, temperature is much easier to control when you cook with gas.) Stir in 2 cups pecans and 1 teaspoon vanilla. Pour onto cookie sheet, store overnight in refrigerator. Cut into small squares. Melt 1 block paraffin, 2 large (9 1/4 ounce) Hershey bars. Dip squares in chocolate; cool on wax paper.