Can you do it? Yes. Should you? No. Have I towed over weight? Yes. In fact today, I was at 9,940 with rock in the bed and my gvw is 9,200. I wouldn't do this on the freeway or more than a couple miles even tho I have much higher rated tires than stock.
That being said, I've blown a tranny being 2,000 pounds under gcvw. My parents pull a 4,200 dry TT behind their 2006 crew cab Tacoma. I'm sure they are close or over both gvw and gcvw after the canopy, generators, water, etc. They drove back from Indiana to western Washington through the mountains of new Mexico, Arizona, California, Utah, etc.
Now, I'm not wealthy but do I enough to own an 08 Duramax with 120,000 miles for my 5,200 dry toy hauler. I'm about 8,000 pounds wet with 3 quads. I recently went on a trip with 3 other campers and all three other dudes had to get in my truck to scope out a site. All of them commented how much better mine pulled than theirs. I have pulled close to over weight and I didn't like it. Now I put it on cruise control and drive stress free.
Really it's up to you. I personally will never be close to over again, but I many people do that.
