Originally Posted by JDiver

The connection is very tight even if Finnair and AA (as your flights are marketed by Finnair but operated by American, it's all Terminal 8, but Finnair would also arrive / depart here) share terminal 8 - you must clear Immigration and Customs (retrieve your baggage at the carousel, pass through Customs and return your baggage to the counter just outside of Customs), pass through TSA security back airside, etc. (I'd personally never book or recommend a JFK connection under two hours.)