I have a 98 4.0 and I was just given a hulk of a 99 ranger with the 4.0 motor mostly intact. what do I have to do to make it work? mine is a Manual and the 99 is automatic... will my computer work with that motor or do i need the one from it? can anyone give me a list of i have to change or not?

 

1998 and 1999 Ranger 4.0l OHV would be direct swap

You will need the Flywheel from the 1998 and the Cam synchronizer and sensor(1999 used a 2 wire sensor, 1998 computer needs the 3 wire model)
Or get a new 1998 cam synchro/sensor, as these should be changed ever 100k miles or so

You will use the 1998 engine wiring harness on the 1999 engine, will be plug and play

Also use the Block Plate from the 1998 on the 1999 engine. this is the thin metal plate between engine and bell housing, it is there to align starter motor with flywheel, its also a shim so needs to be there

I would put in a new Rear Main seal on the 1999 4.0l when flex plate(auto) is off and before installing the flywheel(manual), they are not expensive and hard to change if they leak after engine is in

Oil pan gasket is your call, if 1999 shows signs if leaks then I would put in a new gasket, as its a real pain to do it once engine is in vehicle
If you do remove the oil pan then I would change the oil pump, just because, but if oil pan looks good, no past leaks, then skip the oil pump, its not a known issue on the 4.0l OHV

 

Thanx Ron ... You are the MAN!