In 2 weeks, we (a total of 5 people) are coming back from Australia: SYD-LAX-JFK. Owing to a schedule change, we now have just 1 h 20 min between DL 16 (arriving 6:10) and DL 78 (departing 7:30). How doable would this be?

Of course DL will let us change the LAX-JFK flight, but seeing that the next direct flight isn't before 11:30 makes me kinda reluctant... I'd positively hate to see us clear customs in time for the earlier flight and then be stuck there for 4 hours because there'd be no more seats on the 7:30. (And even if there are, our bags would be on the later flight...) OTOH, given that we're 5, I can see some challenge if we do misconnect and have to fight our way onto the next flight.

Thanks in advance for any advice!