You are aware by now that you're dimensional weight is calculated by doing length X width X height / 139.
If that number is higher than your actual weight... you will pay for the dimensional weight of your shipment.
But you, the sophisticated shipper, already know that NOTHING with the carriers is set in stone.
There are ways of getting the carrier to change that 139! To 166, or 194 or sometimes even 225.
This results in a large decrease to your dimensional weight.
(If you're dividing by 225 instead of 139 you get a much lower number.)
HOW CAN YOU GET YOUR CUSTOM DIMENSIONAL DIVISOR?
speak to your rep
speak to the ShipBoss experts (if your rep says no or if you're too busy)