If you consider buying it, I would surely get in touch with the seller to ask the part number cast into the side. Don't tell him you know anything about the different numbers, just ask for the number.
Then you can start to make an informed decision.
If your car is running OK with its current -14 head, there's no reason to go out and get another -14 head in my opinion. Not enough of a gain to be worth anything. Now if you have a -14 head that's already cracked, then you might want to gamble......
Ken300D