GMPartsGiant.com offers the wholesale prices for genuine 2020 GMC Yukon XL 4WD parts. Parts like Sunroof Drainage are shipped directly from authorized GM dealers and backed by the manufacturer's warranty. Parts fit for the following vehicle options. Engine: 8 Cyl 5.3L, 8 Cyl 6.2L. Model Code: 1500 4 DOOR.