wheel opening moulding are standard on 14-18 gmc,,although your pics looks as though the truck has some type of front as well as rear mud flat extensions, not really able to tell if they are added to factory mouldings
appears you may have 2 problems have you looked in upper corner on drivers side looking in thru grill? that location is usually #1 place for freon leak. that location is upper corner of a/c condenser