I know this question gets asked all the time..we arrive at JFK via Delta (Comair) at 4:28 pm in Terminal 3, then depart on Swiss Air for Zurich at 6:10 pm in Terminal 4. This gives us 1 hour and 42 minutes. Will we be running to make our connection or is this plenty of time?

Assuming your inbound is on time, you will have plenty of time to connect. Enjoy the duty free shopping as well!

If your Delta flight is not on time, you will have to run in order to catch the international flight. Going through the customs at JFK takes a lot of time too. Be sure you don't have to pick up your luggage at JFK and register them for Zurich. We nearly missed our flight from Montreal to Quebec last summer as the New York/Montreal flight was late and for all the reasons above. We live in Paris and usually go to the airport 3 hours before departure for transatlantic fligths, especially in JFK, because there are very long lines for checking and going through the customs.

We are probably just taking carry on luggage for this trip. Will that make a difference?

customs???

Maybe you know something, but would the OP have to go through customs?