An agricultural harvesting head for an agricultural harvester comprising: a left frame section disposed to receive crop harvested on a left side of the agricultural harvesting head; a right frame section disposed to receive crop harvested on the right side of the agricultural harvesting head; a center frame section that is coupled to and disposed to receive the crop harvested from the left frame section and from the right frame section; the center frame section comprising two laterally spaced apart vertical side members (310, 312), an upper horizontal member and a lower horizontal member, wherein the two vertical side members (310, 312) and the upper and lower horizontal members (314, 316) are fixed together at their ends to define a central aperture that is dimensioned to pass substantially all crop harvested by the agricultural harvesting head, wherein the central aperture has an upper left corner, an upper right corner, a lower left corner, and a lower right corner, an adapter frame disposed behind the center frame section; the adapter frame comprising two additional laterally spaced apart vertical side members (318, 320), an additional upper horizontal member, and an additional lower horizontal member, wherein the two additional vertical side members (318, 320) and the additional upper and lower horizontal members (322, 324) are fixed together at their ends to define a central aperture that is dimensioned to pass substantially all crop harvested by the agricultural harvesting head, wherein the central aperture has an upper left corner, an upper right corner, a lower left corner, and a lower right corner, and an upper left link, an upper right link, a lower left link, and a lower right link that couple the adapter frame to the center frame section, characterized in that the upper left link and the upper right link extend forwardly and outwardly from their mounting points on the adapter frame to their mounting points on the center frame section, that the lower left link and the lower right link extend forwardly and inwardly from their mounting points on the adapter frame to their mounting points on the center frame section, that each of the four links is pivotally coupled at its rear end adjacent to the adapter frame at one of the four corners, and that each of the four links is pivotally coupled at its forward end adjacent to the center frame section at one of the four corners. a left frame section disposed to receive crop harvested on a left side of the agricultural harvesting head; a right frame section disposed to receive crop harvested on the right side of the agricultural harvesting head; a center frame section that is coupled to and disposed to receive the crop harvested from the left frame section and from the right frame section; the center frame section comprising two laterally spaced apart vertical side members (310, 312), an upper horizontal member and a lower horizontal member, wherein the two vertical side members (310, 312) and the upper and lower horizontal members (314, 316) are fixed together at their ends to define a central aperture that is dimensioned to pass substantially all crop harvested by the agricultural harvesting head, wherein the central aperture has an upper left corner, an upper right corner, a lower left corner, and a lower right corner, an adapter frame disposed behind the center frame section; the adapter frame comprising two additional laterally spaced apart vertical side members (318, 320), an additional upper horizontal member, and an additional lower horizontal member, wherein the two additional vertical side members (318, 320) and the additional upper and lower horizontal members (322, 324) are fixed together at their ends to define a central aperture that is dimensioned to pass substantially all crop harvested by the agricultural harvesting head, wherein the central aperture has an upper left corner, an upper right corner, a lower left corner, and a lower right corner, and an upper left link, an upper right link, a lower left link, and a lower right link that couple the adapter frame to the center frame section, characterized in that the upper left link and the upper right link extend forwardly and outwardly from their mounting points on the adapter frame to their mounting points on the center frame section, that the lower left link and the lower right link extend forwardly and inwardly from their mounting points on the adapter frame to their mounting points on the center frame section, that each of the four links is pivotally coupled at its rear end adjacent to the adapter frame at one of the four corners, and that each of the four links is pivotally coupled at its forward end adjacent to the center frame section at one of the four corners.