Most I've had in the bed was 4,000 pounds of gravel. Didn't hit the helper pads, truck handled it fine.

Most I've weighed in at overall on a scale was just over 18,500 pounds pulling a double axle dump trailer filled with dirt.

 

I have carried a set of Toyota axles and a bunch of Crap all winter, just over a 1000LB and you would not even know it was there. The other day, I added an Allison 1200 tranny for my buddy and it still looked like it had nothing in it LOL!

 

Here I am 2 years ago with the lumber for a 16X22 foot deck, a couch, a lazy-boy and my 6500 lb camper. I couldn't hardly tell it was back there. What a motor!

 

I picked up 2 pallets of 12"x12"x2" pavers for my neighbor at the Homey Depot and the only thing that let me know they were back there was the near total lack of brakes. Scary. Truck rode nice, though.

BTW, I took off the liftgate recently and I've been enjoying the unburdened power of the beast. I didn't realize how quick the ol' girl was until I unhitched that 600 lbs.