a header;

a tractor having a power unit;

a crop cutting and transfer system on the header for cutting a standing crop and transferring the standing crop after cutting to a discharge opening of the header;

the crop cutting and transfer system including at least one hydraulic motor for driving the crop cutting and transfer system;

a crop conditioner system at the discharge opening for conditioning the cut crop from the discharge;

the crop conditioner system having a hydraulic motor for driving the crop conditioner system;

at least one hydraulic pump driven by the power unit on the tractor having a pump input for generating pressurized flow in hydraulic fluid at a pump output for driving the motor of the cutting system and for driving the motor of the conditioner system;

a first circuit arranged for supplying the hydraulic fluid from the at least one pump to the motor of the crop cutting system and the motor of the crop conditioner system for driving both motors in a forward direction for crop harvesting;

the first circuit including a first variable rate valve for controlling a rate of flow of fluid to the at least one motor of the cutting system for controlling the speed thereof and a second variable rate valve for controlling a rate of flow of fluid to the motor of the conditioner system for controlling the speed thereof;

the first circuit including a return drain and filter for return of fluid to the at least one pump after driving the motor of the cutting system and the motor of the conditioner system;

and a second circuit including a reverse control valve for supplying, with flow of fluid through the first and second variable rate valves halted, the hydraulic fluid from the at least one pump to the at least one motor of the crop cutting system and the motor of the crop conditioner system for driving the motors in a reverse direction for releasing a crop blockage.