Actually, I now believe I have the 1/2 ton suburban. It has 6 lug nuts, not 8 on each wheel. In the door on the yellow sticker, it says "The combined weight of occupants and cargo should never exceed 1402lbs." Is this what y'all are talking about when you say "payload"? Also, when calculating that, If I weight 170lbs, my wife is approx. 140lbs, each of two children are about 32lbs, and a 14lb dog, 2 small suitcases - I think we are ok...?
With all that being said, that reduces my towable weight substantially.
Also, does a 3/4 ton suburban look different than the 1/2? I would imagine it did since the normal trucks do. If so, I don't think I have ever seen one. I am currently looking at the 250's, and 2500's so we have a better TV.