One New Replacement Vertical Two-Piece Muffler with Pipe and Clamp for Ford/New Holland Tractor models: 501, 600, 700, 2000 (4-Cylinder, 1953-1964), NAA — all with 134 CID Gas Engines, and 4000 (4-Cylinder, 1958-1964) — with 172 CID Gas Engines Pipe Inlet: 1-5/8″ ID Pipe Outlet: 1-3/4″ OD Replaces Part Number: and Models This part fits: 500, 501, 600, 700, 800, 900 Series, NAA 501 601 700 2000 800 900 4000 4-Cylinder, NAA Jubilee Reference Numbers: FD1210, M103, FD1210, FD1210-A