Not sure about casting numbers.
If you look here and scroll down to the Lima Engines:
Ford Pinto engine - Wikipedia, the free encyclopedia
You will see the history of the 4 cylinder engines used in Rangers and other Ford models.
The Ranger 2.0l, 2.3l, and 2.5l SOHC are basically the same engines
2.3l is a bored out 2.0l
2.5l is a stroked 2.3l
The 2.3l DOHC Duratec replaced the Lima engines in mid-2001