Ford might not want to make the info available, but Hella published this:
http://www.hella.com/startersalterna...rge_system.pdf
I suspect the following comment in the Century Yuasa info sheet is a major reason why the OE Ford batteries are silver calcium, and why the replacement Motorcraft batteries are not:
This provides car exporters with an increased chance of having the batteries retain sufficient charge to start the vehicle by the time they reach their export markets.