I have a 2013 I use for my landscape business. Around 75,000 miles right now. Every single day, that truck is ready to go to work and it does everything I ask of it.
When we had a Work & Play TT, I used it for about six months. Mostly 400-500 mile round-trips. My truck had the 3.73. Once you get up to highway speeds, it does pretty well. Inclines would mean as much as dropping from 6th to 3rd sometimes. Revving is just a part of life when towing with this motor but it doesn't mind it.
If you're insistent on getting a gasser, its a great engine. But as others have said, that's a lot of weight for most any gas engine. Check that axle ratio and hopefully, its a 4.30. A 3.73 would be really tough and a 3.55 would be a deal breaker in my opinion.