PHX, SAN tend to get the 73H. SLC, SEA, LAS can be unpredictable. DEN and SJU tend to be 73Y. However that does not mean much since both have the same seating configuration if one develops a mechanical problem Delta will swap the other type in if that is what is available. One of the reasons I used to avoid the 737 when Delta flew them JFK-LAX if I could because I always seemed to get swapped out to a plane with overhead video. As soon as I saw a Gate 1 departure I knew it meant that I was not going to have PTV though now that all of them have winglets it is less of a tell