Well,for what it is worth - here is my story!
I live in Burlington Ont,. and last September, I bought a 2005 Airstream Classic 30' (which is actually 31 ' bumper to ball and differs only in internal layout from your Classic 31')
I towed the trailer home to Burlington with our GMC Sierra 1500
extended cab 4x4 with 4.10 diff.
I had no trouble towing it home power-wise, but then, as you likely know roads are pretty flat between Ohio and Ontario.
I did encounter some sway at 65 mph (as fast as I should be going anyway!) which I had never experienced before with our 27 foot Award trailer even at 75-80mph.
That convinced me to buy the Hensley hitch which I had long been considering anyway.
Given that I intend buying a bigger truck (read on!) I might not have needed the Hensley, but I figured it surely couldn't hurt!
I have only recently installed the Hensley and have not yet driven at interstate speeds with it. Up to 100kph on highway 6, driving to our trailer back and forth to our storage spot, it seems rock solid and I think it will be a real plus in terms of safety/relaxing towing.
For my part, I am now actively shopping for a GMC Sierra 2500HD diesel 4x4 short box, primarily to ensure I have enough grunt, but also to further improve stability
From everything I have read, ( and I read a lot!) the 3/4 ton seems to be considered the ideal match to the size trailer that you and I have. I have a lead on one and may buy it next Monday.
If I cannot negotiate a good deal soon, then I will use our present Sierra 1/2 ton 4x4 to pull the trailer to Arizona this winter (we go every year).
I will then order a new truck next year once I know which companies are still in business!
I think that with the Hensley, our 1/2 ton will be fine for sway, and I will just have to go up those long hills in the SW USA a bit more slowly than I would with the
Duramax Diesel / Allison tranny combination that I crave!
I would certainly not want to pull a 31 ft Airstream with anything less than the
1/2 ton/Hensley combination. Despite what the London Airstream dealer advertises, I for one would never consider a car as a TV for a 31 footer - nor a short wheel based SUV.
I am no expert, but I have been towing for quite a few years!
Before towing our previous 27ft Award with a pickup, we used a Safari 4wd minivan. Power was adequate, but I was always gripping the wheel real tight! I couldn't believe the difference when I moved to thelonger wheel based truck.
No doubt other people's opinions may differ from mine, but i am a firm believer in "having too much truck is better than not enough for safety and relaxed driving."
Hope I don't get flamed too much for stating my opinions - and considered opinions is all they are, believe me!
There is only one word of caution I would offer - not from personal experience but from what I have read on the forums.
Many folks say that a really big tow vehicle or oversized spring bars can transmit too much jolting back to your trailer and cause damage such as popped rivets, frame separation, and cracked frames.
For that reason, I plan to stay away from one ton trucks, even though I could get a good deal on one, and I do not intend to tension my 1000# spring bars very much.
Along the same lines I will go for a Chev/GMC as I hear that their ride is softer than Dodge or Ford.
I am even wondering if it might be a good idea to buy a set of 750# bars for my Hensley instead of the 1000# bars.
I think that with a 3/4 or 1ton truck you hardly need spring bars - except that with a Hensley hitch, you do need them to hold all the hitch components properly in place, although you don't need to apply a lot of tension,
Good luck with whatever you decide!
Brian M.......... Burlington Ontario,
For what it may be worth, if I can help at all, please email me!