For example, Code "G" for the engine (fifth character in the VIN) is a 406 in 1962 - 63.
However, code "G" in 1969 - 70 is a Boss 302.
There are lots of codes for each model year. A CD or paper (preferred) copy of the Ford Master Parts Catalog is a good reference, so is the factory shop manual for each particular car line.
1912 Model T Ford touring Salmon (ugh!)
1913 Model T Ford Touring original Black paint
1915 Model T Ford Roadster Black
1915 Model T Ford touring Black of course!
1967 Cougar GT 390 Cardinal Red / Black
1968 Cougar GTE 427 Augusta Green / Saddle
http://www.supermotors.net/vehicles/registry/15029/50071-2