Part Number: 020-42912-17 (Upper orifice assy)Part Number: 020-42912-20 (Upper orifice assy)Part Number: 020-42912-21 (Upper orifice assy)Part Number: 020-42912-22 (Upper orifice assy)Part Number: 020-42912-23 (Upper orifice assy)Part Number: 020-42912-24 (Upper orifice assy)Part Number: 020-42912-25 (Upper orifice assy)Part Number: 020-42912-26 (Upper orifice assy)Part Number: 020-42912-28 (Upper orifice assy)