Setting a Shipping rate for a specific item that is measured in dimensional weight.

[David243]

I have an item that is 35" x 33" x 5".  The actual weight of the item is 10lbs, but when you enter the dimensions into the computer it changes the weight to 55lbs. (dimensional weight)  I am using parcelify and I want to create a shipping rate for this specific item.  How can I do that?