Nice situation, ay? Glad you are happy with your new truck. I stand with you. I recently upgraded from a 2016 Sierra 1500 to a 2016 Silverado 2500HD with Duramax. I was struggling with what to do because the 1500 was at its max gross weight. It was fine towing on decent roads and would scream up the mountains out west, but I80 concrete roads and bridges got to us. Too much porpoising. I added Timbrens, but the ride was rock hard. I looked at both Ford and GM 3/4 ton gassers, but was afraid that I would not like the power loss after the great pulling power of the 5.3L. 3.5l Ford would be similar. More power to weight ratio than the 3/4 ton gassers. I found a great deal on the used Duramax (20k miles) and pulled the trigger. Am very happy with the change in power and weight. Pulls like a beast and is quite comfortable. Not as soft a ride as the Sierra, but everything is a tradeoff. Bottom line, if your tow vehicle is near its max, it is best to upgrade if you can afford it. If you can't or don't want to upgrade, it might be good to downsize the trailer. A lot of it also depends on how much you tow. For short trips, marginal can be okay.