When ordering a 2005 to 2008 remanufactured 5.4L 3v or 6.8L 3v engine, spark plug boots may be provided in the packaging. Replace all black spark plug boots from the original engine with the 'brown' spark plug boots, as provided. The updated 'brown' spark plug boots are longer than the black boots to accommodate a running change in the spark plug length. The ignition coil bodies and spring/resistor are transferable and only the rubber boots require replacement. Failure to install the spark plug boots provided with the replacement engine could lead to drivability concerns.