If you are going through customs, I don't know if you can make it. However, if you are not and you did not check luggage, it should be fairly easy. Just take the Airtrain (it's free) to terminal 3 (ask airport personnel for directions to the Airtrain). If you have luggage that you have to wait for, do the same thing but RUN!
I would also contact Delta and let them know that you are connecting from an AA flight and tell them your flight number. They may wait for you.
Good luck!
If you are going through