Can I use this?

[Nima]

Hi everybody;
This week I have 3 days weekend! and today is the only day that my wife is at work and I am home! therefore I took advantage and paid a visit to a junk yard and bought these things. Radiator reserve tank fits nicely, I just have to clean it up but my question is about the alternator. I took it off of blazer which I don't know what year since it was all smashed and I am not good at estimated the ageanyway. On the partial option list in the glove box of the truck, looked like truck had lots of options including heavy duty batery and some electrical stuff. I don't see any part number on this thing most likely because I am not looking at the right place!. Now, the question is; I have external regulator alt. Do you think I can use this one? Thanks