A crop harvesting header includes a cutter bar mounted on a frame carrying a plurality of generally horizontal cutter disks. The cutter bar includes a first longitudinally extending hollow gear case and a second longitudinally extending hollow gear case divided at a position along the length of the cutter bar so as to form first and second separate sections. Each gear case includes a gear train of spur gears to drive the cutter disks. On each section the outermost disk is connected to an upstanding drive shaft with a right angle gear box connected to an upper end with a drive transfer shaft connecting the first and second gear boxes, an input hydraulic drive motor to the first gear box and an output shaft and the second gear box for driving the conditioner.