I had almost 80,000 km on my Duratracs (275/70/18) when I got a bolt through the side wall and other than being louder than stock I thought they were great tires. I have a '10 1500 but have pulled a 8500 lb trailer and thought the tires handled that just fine. I've never had any of the issues you describe..
A friend of mine loaned me his 30' camping trailer. Pulled it home with my truck. Decided to take one of the 2500's from work to take it camping though...
Ended up taking a 2500 from work to tow it up to Mosport. Pulls SOOO much better with a 3/4 ton than a 1/2 ton!!
Thanks!! He actually also has a 1940 in his barn too that was his grandfather's but it needs a TON of work. This one needs really only interior, some wiring, lights etc...
Over the weekend took a 3,000 km round trip to pick up a 1939 Studebaker Commander my friend bought. Truck pulled it Easy! Could barely tell a difference towing the empty trailer vs loaded.
Here's some pics.