It's easy to get the EVTM's for both the earlier Rangers and the Explorers but the wiring to put a '96/97 Expo V8 into your '92 Ranger won't be plug and play.
The Expo's main engine to body connection is a 42 pin plug that uses all but a half dozen or so of the pins. But, don't let that scare you off. Everything from the back up lights, neutral safety switch, all the dash instruments to the fuel pump relay go through there. To get the ECU to fire up the engine only really takes a handful of power and grounds, the rest is all contained within the harness.
The difficulty comes from Ford changing the ECU locations. Pretty sure your '92 has the ECU under the dash on the right side. Starting about '93 or 4, the ECU moved to under the hood in a weather tight pocket right above the engine. Might be possible to graft one of those pockets into your Ranger or you'd need to significantly stretch the harness to move the ECU into the cabin. Neither is particularly difficult but especially adding a couple feet to the harness would be tedious.
I'd lay odds that most of the early Ranger V8 conversions use carb'd engines. Greatly simplifies the install, but dang, the later Ford EEC-V engine management system and coil pack ignition is SO much more efficient, particularly with the later overdrive transmissions they came with. (Mo betta stuff!)