The official minimum connecting time is 90 minutes, which you have. This allows for (a) possibly sitting in the back of the plane; (b) going through the non-US-citizen/resident immigration lines, which are longer; (c) waiting for checked bags; and (d) going through the regular security lines in T3. If you can avoid two or more of these, you'll be absolutely fine. Avoid one of them and you will be less absolutely fine. Have them all and you should still be OK, but that will then start to depend on time of day and the other usual factors.
I booked a 1:22 connection from NRT in June. After aa.com sold it to me, I got a call that it was too short and I'd have to take a later flight to BOS. Naturally, I got to the gate of the earlier flight 45 minutes before it left - all of (a) through (d) were in my favor - but by then it had so many standbys they had closed the list. To make things worse, the flight they made me book instead was cancelled, etc., etc... I wrote a letter of complaint and got 5,000 miles, so I guess it wasn't a total loss.
Bottom line: book it, don't worry, but write down the next flight or two to PHL just in case so you'll know what gate to head for if things don't work out.