I have two shipping rules for a particular product.
Case 1. (Shipping box)
Quantity: 1-12 Width: 6 Height: 6 Length: 8.75 Weight: 3
Case 2. (Shipping box)
Quantity: 13-24 Width: 8 Height: 6.5 Length: 11.25 Weight: 4
When a user purchases this particular product, if the quantity below 12, use Case 1 shipping dimensions. If greater than 12, use Case 2.
There's a tutorial on how to achieve something like this but it uses flat rate and not any shipping box dimensions.