proper use of air shocks

You don't want to carry heavy items inside the passenger compartment. I had a friend get killed by a metal tool box that was on the front floorboard of his pickup, he had a roll over accident. The heavy item was extremely fatal.
Do some load relocating

Move the heaviest items to the floor of the back seat. Next heaviest to the back seat least heaviest to the rear (by the latch) of the trunk.

That way you don't have as much weight behind the axle centerline