You've already booked your flights so just want to know whether to worry? 1 hr. 20 mins. sounds like an awfully short connection time, since you'll have to go through Immigration (lines obviously depend on number of other internatonal passengers arriving at the same time, on your and other flights), get your bags, go through Customs (is usually as simple as handing the agent a form as you walk by, but you could be one of the unlucky ones to be stopped), hand your checked bags to a Delta rep at a transit desk, then go to your domestic flight (you'll need to go through security again). However, that combination of flights does show up on Delta's Web site, so they apparently regard it as doable (at least technically). Assuming the two flights were booked together, even if you miss the connection Delta should put you on the next flight to JFK with available seats in your fare class (not necessarily the very next flight). Since there are flights to JFK at 11:30 and 1:30, I'd think your chances are good you'll get to JFK that day.