Just got weighed Friday morning. I was fearful of being worse, but ended up being 20 pounds over on my truck's GVWR. I know for sure I had more than 20 pounds worth of tools in the bed as it was our...
While this doesn't mean it is OK to do, over on the truck camper forum there are folks running 1000# and more over GVWR. And they have been doing it for thousands of miles without incident.
The important figure is axle weight, most frequently limited by tire and rim rating.
I had tires rated to 3970# each when carrying the Eagle Cap truck camper. Way over GVWR but under on RAWR.