Is the number of spring leafs in the main pack the same as the 2004 or did they add another one in your new truck?
New truck is three leaves with a shorter bottom helper leaf. Leaves are significantly thicker.
Old truck is four leaves with a shorter bottom helper leaf plus two overload leaves.
Without the stable loads, my current 2400 pound camper doesn't just touches the overloads on the old truck so I added the stable loads. It did reduce the squat but only slightly helped with the stability.
So it will be interesting to see the difference. Hoping I don't have to add airbags and/or sway bar.