I own a 1993 GMC Suburban K1500 (4 wheel drive) 350 V8. (new rebuilt Good Wrench Engine and New rebuilt transmission). I live in central Wisconsin. The Yukon Suburban Owner's Manual (page 4-58) says this about towing capacity: "For utility vehicles, a trailer should never weigh more than 7000 pounds (6125.6 kg)...but even that can be too heavy. It depends on how you plan to use your rig. For example, speed, altitude, road grades, outside temperature, and how much your vehicle is used to pull a trailer all are important. And, it can also depend on any special equipment that you have on your vehicle." I pull a rock band covered trailer (2500 pounds empty, plus 1000 pounds of loaded trailer stuff, speakers, sub woofers, amps, etc.) Plus, 5 heavy boys ride in the Suburban with 6-8 guitars and sensitive tube amp head units. I always run in 3rd gear, and have an extra tranny cooler in additional to the towing package. Plus, I have a transmission temperature gauge that registers about 165 degrees when towing. I use Mobil 1 Synthetic engine oil, and have the tranny oil changed frequently based on the miles I put on the Suburban. Here is the "opinion part" of this post: I would be confident about pulling a 6000+ pound trailer, but would religiously watch the tranny temperature gauge, and limit the speed to 50-60 max, depending on conditions. Winter towing is easy. But hot summer towing is the true test. 7000 pounds is too heavy for a 350 V8 despite my equipment and cautious pulling attitude.