Minimum Connect Times:
Connecting at JFK
Incoming airline US
Outgoing airline CX
Flight type Domestic to International
ONLINE 1.00 1.15 1.45 2.00
OFFLINE 1.00 1.15 1.45 2.00
** OR * ARE ALL
**-CX DI 1.55
US-** DI 1.30
I'd look into this if I were you. I'm no JFK expert but my trips through there suggest you may have a tight schedule.
There is a train landside that goes around in a circle between terminals, and it takes quite a while to go the whole loop. I don't know if one of the loops lets you go from T8 to T7 without going all the way around. Also, since the train is landside, you'll have to go through security. I would check to see if there is any way to transfer airside.
Sorry, just joined and thought I would chime in - I don't know of any airside transfer at JFK, especially between terminal 8 and 7.
It is tight, but doable if the lines at T7 aren't too bad. You'll want the "yellow" AirTrain, which runs between the terminals only and operates from T8 to T1 (so T7 would be the next station), instead of the red/green trains, which will go from T8 to T1 (you'll have to go all the way around). However, check the signs (which sometimes work) or ask a red jacket in case there are delays or other issues.
According to their website (AirTrain), you'll be traveling in off-peak periods - so 15/20 minutes between trains, which eats into your connection time quite significantly.
Just to chime in, AirTrain may end up running every 30 minutes at this time of night, just from previous experience. You could walk from one terminal to another as well, it is not that crazy of a walk, but it would not be a pedestrian walkway, so if you have a lot of luggage, it may be difficult.