I've got an Equalizer hitch and only towing 4000 lbs and 350lb tongue weight and my back end sags. I have the tow package, and off road package . No adjustment on the hitch has been able to reduce it.
seriously, after all this time , still no one makes one. With the crew cab and the 5'ish bed, carrying extra fuel in the bed is also a pain when traveling long distances.
The small tank is my biggest complaint, on long distance towing trips getting < 10 mpg I'm stopping every 2 -3 hours to fill up just in case I have to drive farther between stations, I'd kill for another 20 gallon tank.
I think I may have found the culprit. I keep bottles of emergency water under the back seat, they freeze and thaw and sweat. That may be the cause. I pulled them out to see if anything changes.
A little late on this one , but I had a 2017 LTZ Z71 2500hd with the tow mirrors and really liked them, my 2019 1500 LTZ Z71 with tow package mirrors work just fine. I recently towed my travel trailer 4000 miles without any issues. There were a couple of times that I wished I had the bigger mirrors but managed just fine.
I found mine under the back seat in the storage compartment. I could not figure out what they were for and I HAVE A TRAILER! I didn't even think about it until I saw it on this forum earlier today in another post. I wish I knew because I was traveling out in the Midwest 4 weeks after I got the truck and blew a tire on my trailer. I replaced all four tires and had them put metal valve stems in because I knew I wanted to get sensors after I had that blow out. I think had I had them on, I would have saved myself a lot of damage to the trailer as it was about 100 yards of driving before I even realized the tire had blown.