It should still have overdrive though.
EDIT: here we go; "4R55E T 1995-2001 4.0L Rangers 4-Speed 2.47 / 1.47 / 1.00 / 0.75"
0.75 would be overdrive. This came from the tech library by the way.
I can't think of many cars at ALLL nowadays that don't have overdrive.
That being said, your Ranger will pull that trailer just fine.
If my dad's Suzuki XL-7 can pull my Ranger on a car trailer, then I'm sure your Ranger can pull this trailer (we also have a 02 Starcraft that wieghs in at 3100 loaded I think, and we pull that with our XL too). I've seen Rangers pulling some large loads just fine.
If it is rated at 5K lbs (I don't know, but that is just the number that has been said), then that is how much the company "says" you can pull, but for the most part you don't really want to exceed that even if you can get it moving, because it is stopping more weight than that, that is the problem. And parts tend to wear out faster if you don't know how to tow that much weight.
Also, I am going to have to agree with Will on the shifting issue, entirely. My tranny lived fine going over the Cascades (I go over them often) in 3rd gear, but once I left it in 4th (overdrive) and it started blowing smoke at the top. This was becuase in 3rd (D) it did not hunt for gears, but in OD, it had to hunt, which killed it.