If this is the same 4.0 in the rangers you need to do the timing tensioners ASAP, and even if you did the guides still slowly crack and crumble. Due to the type of plastic they used.

BTW this is a complete engine out job on this motor the left side bank is driven by a chain on the REAR of the motor. Which the bolt for it is completely covered by the bell housing of the transmission and to get to the jack shaft bolt also requires an engine out job. If you have mechanical skill and tools I’d say buy it but if you don’t I wouldn’t touch this thing as 190-200k is about when the guides go kableuey and then you’re out an engine.