Mustang Modern Power Steering Borgeson Conversion Upgrade Kit 1971 1972 1973. The Borgeson conversion box is a new modern Delphi 600 series integral power steering gearbox with true modern power steering feel, feedback and a quick 14:1 ratio. Borgeson has manufactured this box to bolt directly to the factory mounting location and to fit the stock power steering linkage without any modifications. The original factory steering coupler will need to be changed with the supplied coupler to fit the new steering box input shaft. Included hose kit to suit Saginaw style pump. SKU: D1ZZ-MS-PS-CK Brand: UPC. We will respond to you within 24 hours and do our best to help you out!