Dude, I'll run a snatch block all the time, if possible, it helps the winch live a longer life.

And under the best conditions, using GVWR means a 9000 is the minimum winch since under most conditions, they will not be ideal. (GM...I believe all mfgrs...determines curb weight as vehicle weight as shipped from factory, with a full tank of fuel (fuel not shipped from factory, but the weight is figured into the calculation). But then the dealer adds on stuff (like brush guards, etc.) and then you have to make sure you get the rating for the correct vehicle since trans/engine/standard vs. luxuray, adventure vs. non-adventure, etc. will be different. So, the best is to get it weighed at a reliable station.
But I agree, it is very easy to add weight such as undercarriage, roof cross members, baskets, wheels, different tires, big dog, tons of tools and yea, four 200 pounders. So, 6k is probably a good number to use.
And if in deep mud, boost that figure to around 9K, thus a winch of 13500, so a snatch block or a heck of a large winch is required, and before winching, throw all the big dudes (or dudettes) out of the vehicle.
