Crankshaft Remachined Allis Chalmers 301 20/20 Rods & Mains 6 Cyl DIESEL 4022491, 4020345, 4023823, 4022256, 4512316 ?G2800, D2800, D2900, 180, 185,XT190 Tractors Stroke: 4.25" Rod: 2.373" Main: 2.748" Fits early model engines with cam driven oil pump and long (approx 2 1/8?) front main journal length. Flywheel flange has 4 bolt holes and 2 dowel pin holes.