Look for subtitle files specifically labeled as "English Forced." These only display text when characters speak Italian, which is how the movie was originally intended to be seen.
Here is the "proper text" for the most famous opening monologue often used for testing subtitles: The Godfather YIFY
If you are looking for the dialogue text to accompany a YIFY release of The Godfather (1972), you are likely searching for the specifically. Look for subtitle files specifically labeled as "English