"Model N tractor engine" . "2.921" . . "4-speed manual (8N)" . . . . . "1939" . . "Ford N-series tractor" . . "1.778" . "N-series" . "tractors designed by Ferguson" . "an all-new model" . . "1.64465" . "1952" . "Ford N-series tractor" . . . "3-speed manual (9N, 2N)" . . "1093176.0" . . "Ford 9N" . .