I have a question or two about towing. It's been a while since I had to figure out tow ratings and such. I used to tow a trailer for work 3 Z-turn mowers +equip. But that was with a 2500 4x4 truck and was about 10 years ago. I have a 2006 Silverado crew cab L59, 3.23 rear gear, with the HD towing pkg. From what I'm reading from my owners manual, I can tow approx 6700# max with the gears I have or 7,700# if I had 3.73 gears. I'm wondering if what I have now would be enough to tow a single car trailer 7'x17' with a 3300# car or a 4000# suv on board? Or would it be worth my time to upgrade my rear gears? I would probably be towing 6,000 miles a year.