The adjustable separator grate was introduced in 1997 models. Although the combine still has 4 reverse bars on the separator side they are normally not required. Eliminating reverse bars decreases power requirments and helps straw and cob breakup. The only crop I have seen a need for reverse bars is barley. In most crops half the wires can be removed from the separator side to increase capacity, especially in green material and corn. A high wire separator grate is now available from parts.