The 4R70W comes in two basic cases, the engine bolt patterns. Look at the starter bolts, the 302 4R70W has two starter bolts. All of the "modular" versions of the 4R70W have three starter bolts.
You OP with a 97 Explorer do have to have the output shaft and housing with the speed sensor in it. You can swap almost any internal parts from 4R to 4R, but you have to know those details when selecting one and for the builder/installer.
BTW, for the best latest 4R70W for the SBF's, get the 2004 Mustang V6 trans. That is the last of the 4R's that bolt to the SBF, plus it already has the "J Mod" in it and all internal upgrades ever used up till then.
The J Mod should only be done on the car trans, not the trucks VB. The truck VB's for some reason are always different enough in calibrations that many VB kits don't perform the way they were intended to(which was done for a car VB).