What Motor Do I have??????

Ok I bought this '97 Metro 2 door and when I got it home I decided to go through it and do a full tune up. Well looking at my manual and some other pics I noticed that it may have the earlier motor in it. I do know that the motor was replaced with another one from a junk yard but dont know what year. Is there a way to tell?? Just so I know what year the motor is so I can get parts. Thanks