You should be able to do it. You'd be landing in T5 (International Terminal) and going to T3. A few things you can control:
(1) Have the immigration/customs forms already filled out during the flight.
(2) Use the bathroom in the plane about 30 min before landing. Seriously.
(3) Once out of the plane, walk very fast to the immigration area; 2-3 minutes delay here can add 20-30 minutes depending on lines. Don't stop for bathrooms etc (that's why you went in the flight, see?). While it is not ok to cut in front of people already in line, it is ok to walk past those walking. Running used to be ok, but since 9/11 who knows, stick to walking fast.
(4) Collect your luggage, use the green customs channel, but do not go past the swinging doors. Instead find the AA counter and check in your bags with them; they should give you boarding pass too. (If you go past the swinging doors and see people waiting to receive travelers, stop and turn around! Don't leave secure area with your luggage, it'd make your life quite a bit harder.)
(5) Take the airport train to T3. Once there, you can use any security line to go in. Again, don't have anything on you (liquids, sharp metals, etc) that would delay you at security, walk fast to your gate.
That's it. One secret at any unfamiliar place and tight schedule is not to guess answers yourself but keep asking questions and reconfirming the answers with at least one other person as you walk.