A Toploader transmission is a manually shifted three and four speed gearbox introduced in 1963 by the Ford Motor Company to replace the BorgWarner T-10. It was used in most Fords and Mercurys from 1964 until 1973 as well as some foreign models. Officially designated the 3.03 three speed or Ford design four speed. The 3.03 is the centerline distance between counter shaft and mainshaft. The Toploader got its name from the fact that the access plate to the inner workings was located on the top of the main case as opposed to the side, a convention used on most gearboxes such as the Ford Dagenham or GM's Saginaw or Muncie. Distinguishing the three speed from the four is as simple as counting the fasteners on the top plate. The four speed has ten; the three, nine. Both the three and four speed t