One New Aftermarket Replacement Muffler that fits the following Ford New Holland Tractor models: 231 (1975-1981 3 Cyl Diesel), 232, 4600 (3 Cyl Diesel), 5000 (1965-1975 4 Cyl Diesel), 5600 (1965-1975 4 Cyl Diesel), 6600 (1965-1975 4 Cyl Diesel), 6700 (1965-1975 4 Cyl Diesel), 7600 (1965-1975 4 Cyl Diesel), 7700 (1965-1975 4 Cyl Diesel) Technical Information: Black muffler with vertical oval body Models this part fits: 231, 232, 4600, 5000, 5600, 6600, 6700, 7600, 7700 Reference numbers: D6NN5230T, D6NN5230T-A, D9NN5230EA17M, D9NN5230EA17M-A