Designed for use on Ford 1993-2004 4.2L 2 valve, 4.6L 4-valve, 5.4L V8, and 6.8L V10 engines when installing timing chains. These engines are not free-wheeling , and if an engine has "jumped time," it is possible the cylinder heads have to be removed because of damage to the valves or pistons. Easily installs over the crankshaft and engine front cover alignment dowel to position the crankshaft at top-dead-center - the correct position for timing chain installation OTC recommends the OTC6024 can be used with OTC6009 and OTC6020 (but it is not required).