An agricultural vehicle crop feeder system having housings defining a crop passage, a conveyor assembly, a rotor, a guide plate, and one or more guide vanes extending from the guide plate. The conveyor assembly propels crop material along a feeder flow direction to the rotor. The rotor has inlet vanes that receive the crop material in a receiving region located below the rotor's axis. The leading edges of the rotor inlet vanes travel towards the receiving region on a first transverse side of the rotor axis and away from the receiving region on a second transverse side of the rotor axis. The guide plate is adjacent the receiving region. The guide vane extends into the crop passage on the first side of the rotor axis, and angled relative to the flow direction with its trailing edge closer to the first rotor axis, in the transverse direction, than the leading edge.