FordPartsGiant.com offers the wholesale prices for genuine 2010 Ford Flex parts. Parts like Cylinder Head Cover are shipped directly from authorized Ford dealers and backed by the manufacturer's warranty. Parts fit for the following vehicle options. Engine: 6 Cyl 3.5L DOHC T/C, 6 Cyl 3.5L DOHC VCT SMPI. Transmission: 6-Speed Automatic Transmission 6F50, 6-Speed Automatic Transmission 6F55.