Probably not. Directly under the unit is the return air and some have added extra return air under there. You can, however, open your supply vents by cutting some or all of the fins off (if you remove every other fin no one will notice and it makes a huge difference) them and while your doing that remove the mounting pipe and shorten it so it doesn't partually block the ducts. Some have also added more supply vents.
Dick, Joyce, Diego, Picatso and Gustav
2017 3720 RL, MorRyde pin box
2017 3500 Dodge Maxi DRW 4X4, Pullrite Hitch, IS, Disk Brakes, 3rd AC, Winegard Traveler, Bathroom door mod, Dometic 320, couch for desk swap, etc.