90 min is quite tight, depends on the line at immigration I would say. Delta and Cathay are at the same terminal, after you picked up your bags take an immediate right turn in the arrival hall, go up the escalator one floor, then to the end of the departure hall, very left hand corner. Look for the staff travel desk, usually quite efficient. However, unfortunately no upgrades or jumps.
Register with them and get a number if your flight is full, about 50 min before departure they will try to allocate seats and call out your number if you get on. If loading is light you will get a boarding pass right away.
617 on 24/1 booking does not look great though, only one seat showing at the moment ( internal network, can't give you access code I am afraid)
Best of luck