I wouldn't hit the panic button yet. I think you may be worrying too much about that weight, but you should look at all of the numbers to be sure. G rated tires probably overkill on the truck, but won't hurt. I wouldn't want to do all that tire changing though. If you want to deal with the size and parking issues of the dually, go for it... but if you can't do that (I couldn't as I need to plow), then consider new Bilstein shocks and Timbren springs or airbags for the truck. I did on my 2011 Chev 3500 long-bed diesel and it made a big difference in stability...same with my Ford 6.0 diesel before that.
I will add that I tow lots of miles...25000-30000 on the current combination and about the same or more on the Ford with another Carriage. Long trips, mountains etc. Wore out the shackles and suspension on this Carriage...but no truck related issues with the load. Changed my differential fluid before this trip and it was looking good with no evidence of metal or weight related wear issues at 30,000 miles.
I would be MUCH more worried about the tires on the trailer...lot of tail that could wag your dog there. I would bet they will put Towmaster or similar E rated tires on that rig. If you listen to nothing else anyone says....don't buy that trailer without G rated tires and rims capable of 110 psi. Static weights will likely look ok on paper for a trailer tire in the E range...but dynamic towing weight transfers and other road forces will cause you trouble. Just happened to my friend with his new Keystone Alpine...blew that nice new Towmaster and tore out his sidewall. I had tread separation on my E rated Towmasters. I upgraded. Wish I had insisted at purchase.
An added bonus of the G rated tires is that they greatly improve the stability of the trailer when towing. E rated are like towing on balloons.
Just my 2 cents...enjoy the new rig.
