Go to the auto parts store, they will have all the fittings needed.
Have them pull out a replacement oil pressure switch for your year/engine.
And pull out a PS60 universal oil pressure sender.
Then you can find the fittings you need, there is often not alot of room around the oil pressure switch so take a picture of where it is or better yet have the truck there so you can eyeball any issues
Picture here: http://www.therangerstation.com/foru...d.php?t=140811
Drawing here, 2001 and earlier 2.3l and 2.5l are the same: http://repairguide.autozone.com/znet...3f8021b7e1.gif