An adjustable row unit for a header of an agricultural harvester, the adjustable row unit including a movable deck plate. The movable deck plate is connected to a row unit frame extending in a fore and aft direction of the header. A pivot shaft extends in the fore and aft direction and is pivotably connected to the row unit frame and the deck plate. A rocker assembly connects the deck plate to the pivot shaft for enabling selective positioning of the deck plate relative to the row unit frame in a direction substantially transverse to the fore and aft direction and whereby parallelism between the deck plate and an opposing deck plate is maintained throughout the crop harvesting process.