I have the shipping invoice around here somewhere (I put things in a safe place and find them several years later). Since every configuration is different, i.e. short bed, long bed, gull wing, side box, etc. I would suggest coming up with a combo you like and call them - they were very helpful. Running a Ram 3500 with a 4200 lb payload, I didn't give it much thought - maybe 600 lbs? I'm just guessing. They are made of good heavy duty aluminum diamondplate, and I put probably 300 lbs of tools and parts in the tool boxes and usually run with around 500 - 750 lbs worth of stuff in the bed. We love the load carrying capacity and easy access. I get lots of comments and curiosity seekers at fuel stops and campgrounds. In VA a couple weeks ago, and another Airstreamer was looking at everything until his wife jokingly pulled him away, saying that she could see that he was already spending too much money in his head looking at my "upgrades"... ;-)
"Hot meals, cold beer, dry bed & flush toilet - everything I look for in a wilderness experience..."