I used to tow with an Explorer, rated at 6700... then a burb rated at 8xxx and now I tow with my 97 F250 rated at 8xxx.
As Brimy said, tow ratings are bunk. My F250 is only rated to tow 1500 lbs more than my 95 explorer was, but I would pull 12000 without thinking twice. On lighter vehicles, I would never dream about coming close to the max GVWR.
I will always tow with a 3/4 ton from now on. No stress, no worries. Don't have to worry about how much camping/vacation gear you pack in the back, etc....
Special Thanks and Recommendations to;
PAC Racing Springs
Joint Clutch and Gear