I swapped it out!!!
I used a 99 windstar 3.8 w/95k on it.
Have to do's
use your 98 3.8 intake upper and lower, injectors rails, egr valve and bracket, egr tube, I also used the 4mm intake gaskets as the 98 calls for 3mm and have leakage trouble terribly. the 4mm fit nicely. I also re-used the the 4mm intake gaskets from the 99 and cleaned them perfectly as well as the heads and intake surfaces (do not use wire wheels on the aluminum surfaces they will scuff and scratch easily also no utility blades) i use a flat steel block and 600 grit wet/dry with wd40 on it. I also used the red rtv sealant on both sides of the gaskets. no problems thus far.. i have already put on 250 miles with no ill effects.
You basicly are using the donor block, heads, oil pan, and water pump if you wanna chance that ( i bought a new one didnt want problems with that too hard to change later). you can use any 3.8 engine from 94 thru 2000 that i know of. hope this helps someone out there. oh yeah i also pulled my engine out the top. no problems there either. just remove the cowl panel/s then take all the bull crap off the motor, take your time and label everything make notes of removal sequence also take alot of pics and print them out of all the electrical connections and vaccum lines i found the pics invalubale. tricky things.... power steering pump you need the tool to remove the pully as one bolt hides behind it (the same tool should also re-install the pulley too) mine did. water pump.....you will find the bolts too long to remove as it sits.. once your too the point of stripping the engine down remove the two nuts on the motor mounts. then lift the motor and tranny together about 4 inches that will let you remove the water pump, then set it back down and finish removing the bell housing bolts, starter, converter nuts then pull the motor as usual. oh dont forget to support the tranny in 2 spots with bottle jacks with long boards on top to protect the pan. if you skip this step the tranny will tilt over once motor seperates then you got a mess. I hope this helps someone down the line. go slow be patient and thorough