I'm experiencing a simliar problem with a different Delta itinerary (wholly delta) with unreasonbly short connection time at JFK (can you even imagine it!), therefore I can appreciate your concern. However, my advice, do not even bother to ask Delta reps for assistance, they're plain hopeless.
All you get from them is: "you SHOULD be able to make it, given that Delta is selling this route, however if you were to miss your connection, delta will take all the possible effort to check you in on the following flight"...
DUH!! big deal!!!!!! that's comforting isn't it?