I am seraching for a used engine for 2003 ford explorer, 4.0L, V6, XLS, 4X4. Ford custom said my engine is not flex fuel, but in the car-part.com when put in my VIN#, it show flex fuel(they said VIN K, 8th digit is flex fuel, which my VIN 8th digit is K). I am confused, which one should I pick? thanks.