A corn header for an agricultural harvester is disclosed. The header includes a chassis having first and second lateral ends and a plurality of row units defining crop receiving gaps. The header further includes a power takeoff member having a first end operatively connected to the agricultural harvester. A plurality of chopping units is carried by the chassis adjacent the row units, each chopping unit including a rotating blade configured to span a crop receiving gap of the row unit. A drive assembly including a gearbox, driveshaft and secondary gearbox is operably connected to the second end of the power takeoff member. The drive shaft extends from the gearbox to the secondary gearbox disposed between the first and second lateral ends of the chassis. The drive shaft is operably connected to a rotating line shaft of the row units or the chopping units via the secondary gearbox.