Fellas, Norm Swinford worked for AC for 30 years. When he retired around 1987 he was Product Manager For Tractors.
You all can believe what ever numbers you want to, this is America. But as far as I am concerned, ALLIS CHALMERS FARM EQUIPMENT 1914-1985, by Norm Swinford, is the most reliable source you will find.
page 164: D10 5304, D12 4070.