Dean goes to Southern Connecticut which is located in New Haven. Yale is also located in New Haven. He and Rory are technically always near each other, but it's never mentioned.
Kyle's enlisted rating in the Navy is Aviation Structural Mechanic.
Max Greenfield, who plays Schmidt on New Girl (2011), plays one of Dean's friends who show up with him at Luke's during Dean's bachelor party.
Lorelai quips, "And what are your plans today, Persis Khambatta," a reference to Rory's having gotten a short haircut (Khambatta played a bald Vulcan), Lieutenant Ilia in Star Trek: The Motion Picture (1979).