I’m not recommending that anyone do anything. But RV salesmen do exactly that all day long with zero liability or repercussions whatsoever.
I would have no problems having a wet weight 500-600 lb over my GVWR. I would make some suspension upgrades to my truck to handle the load rather than getting a new truck. And no, the chassis is not going to fail…there are WAY TOO MANY trucks loaded up like this and higher on the road every day…Tacomas, Tundras, Gladiators, and Raptors in Colorado alone make up a substantial data pool. Don’t forget the first two million-mile Tundras. Those trucks were rated for 1300lb of payload driving 77k miles per year bone stock, often carrying 2700lb in the bed. For a million miles each. Imagine the danger everyone was in that whole time! If only they had read Internet forums…but I kid…
I’m sometimes over GVWR with a load of gravel or quikcrete in the bed. One time on a camping trip with my family, I stopped at a CAT scale out of curiosity. My scale ticket said we were 200lb over GVWR. We went all over SW Colorado and did Imogene Pass. My truck handled great and didn’t brake poorly at all. That’s because this number on my door jamb that says “occupants and cargo should not exceed” is a conservatively rated, non-legally-binding CYA for the manufacturer, and I’m fine being a bit over that, especially if I’m not exceeding either GAWR.