Hard to say... the flight is not sold out but you can't view seatmaps for any of the classes (you can view seatmaps on the other morning JFK-SFO flights for tomorrow no problem...just not 837). FLIFO still shows it as a 757, and FLIFO also shows all other flights from SFO/LAX-JFK today are 757's. Keep checking.. if there is an equip swap to a larger plane you may be able to check in later on.