Ok..what Is It?

[David_Hayward (RIP)]

Tony, would that be a 'C11Q-' prefixed number? It appears as though whilst the Ford case is broadly similar to the GM McKinnon one, and may have included as with the GM design, Timken bearings, they differed externally. I suggest at this stage that whilst McKinnons supplied Ford in the early days, Ford's axle plant in Windsor produced their own version to the overall design. Are the Ford and GM cases interchangeable in any way?