Originally Posted by sbm12

Are y'all sure that DL has a counter in T1? They have no operations there so I don't know why they would.

Assuming the bags aren't too big I'd take them to T4 myself and give them to the DL agents there. Saves the interline handoff and you can also make sure of the BPs and other bits for the JFK-SFO flight. The Delta counters are towards the right as you face the security area so closer to the back of the AirTrain assuming you take the one being suggested above. The SkyPriority line is against the far right windows there and the priority security line is easily accessed through there.