Yep, that's too much trailer for that truck. It's gas and has the non-towing friendly gearing. You'd undoubtedly be well over payload and likely over your RAWR with even a minor amount of stuff in the truck or trailer.
For comparison, I have a 9K dry 5th with that truck and it's about all I'd ever want to pull.
Agree 100%. Tail wagging the dog scenario. I have the same truck as you OP and pull a 6k TT with it.
Just came back from a camping trip last week to knoebels in elysburg, pa. There are some big grades going there. Coming up out of lavelle is a 12% grade without much chance to get a runnie at it. I know i was down into 4th or 3rd on that one and 4k plus rpm. This was loaded with wife and boys in the truck, bed loaded with camp fire wood, bikes, chairs, gear, extra water and soda, etc it was heavy.
Once up into those rpms...(sounded great up there by the way) she pulled like a freight train on nitrous...i had to back out of it on the grade becsuse i was catching people! With that said i don't think I'd want much more than 2-3k more loaded trailer weight with my truck, but that's Just me. I like a lot of extra margin.
The 6.4 has A LOT of juice, but like any orher tow rig it has limitations. Once your North of 10k in my opinion your in diesel truck territory. At 11400 dry you'll likely be pushing 13k loaded and that's too much, even for the mighty 6.4.
In my opinion as stated your in drw, cummins territory with that rig. Good luck.
