GMPartsGiant.com offers the wholesale prices for genuine 2018 GMC Canyon 4WD Extended Cab parts. Parts like Brake Electrical System are shipped directly from authorized GM dealers and backed by the manufacturer's warranty. Parts fit for the following vehicle options. Engine: 4 Cyl 2.5L, 4 Cyl 2.8L Diesel, 6 Cyl 3.6L. Model Code: EXTENDED CAB - 6'2" BOX, SLE EXTENDED CAB - 6'2" BOX, SLT EXTENDED CAB - 6'2" BOX.