A header positioning assembly for adjusting a header relative to a chassis includes a lift mechanism configured to couple the header to the chassis, at least one lift actuator configured to apply a force to the lift mechanism to adjust and maintain an orientation of the lift mechanism relative to the chassis, and an adjustment mechanism coupled to the at least one lift actuator or to the lift mechanism. The adjustment mechanism is positionable in at least two orientations and configured so that when the adjustment mechanism is in the at least two orientations, and without uncoupling the adjustment mechanism from the at least one lift actuator or the lift mechanism to which the adjustment mechanism is coupled, the adjustment mechanism changes one or more of a location and a direction of the force applied to the lift mechanism by the at least one lift actuator.