well, your base is the 4x4 package which is nothing really special. just a 4x4 ford. fx4 and 4x4 off road are essentially the same package. 4x4 off was first and then fx4 replaced it in 2002. both of these packages came with the 17 inch wheel package, better shocks (2002+ got ranchos) and full skid plates.
FX4 package did not start unntil 2002. If an older truck says that its because someone just put the stickers on it. My truck didnt have any stickers on it when I bought it used. So I wanted the correct stickers and researched it.
the weird thing is is that i did the research and everything the ''fx4'' should have my truck has
When I was doing my research my 01 has everything the 2002 Fx4 did and they called it 4x4 off road. So that is the stickers I got. Apparently Ford just changed the name of the package in 02. The package stayed the same, just different name.
I thought about the Fx4 stickers cause it just sounds and looks cool. But I decided to put original stickers on it.