Questions for Truck Hardware Gatorback Mud Flap Brackets - Dually - 2015-2019 Silverado/Sierra HD

Will they work with a 21 wide by 24 long bowtie gatorback on a 2018 dually ? I purchased the flaps already thru you. Meant to install on my 1987 dually, now want them on my new truck.

- Bruce Roberts on 11/19/2017