Welcome to the forum
4 Cyl engine needed the engine cross member, V6/V8 wouldn't use it.
Good "been there, done that" articles on V8 conversions here: The Ranger Station - Conversion Index
Best bet is to find a '96/'97 V8 explorer as a donor vehicle, '98 and up can be used you have to deal with PATS(passive anti-theft system) in the '98 and up V8 computers, and Returnless fuel system.
Or you can ditch computer and use carb and distributor setup with any 302/5.0l engine.
Your 7.5" rear axle can be used but won't last long if you use the V8 power much, so swap rear axle for an 8.8" when budget allows, they are found on all 4.0l Rangers and most 4x4 Rangers
Your 1993 dash has mechanical speedometer, uses a speedo cable.
So you need to use a transmission that has speedometer cable hook up, these started disappearing from transmissions in the mid-1990's
Transmission cross member will need to be moved/swapped but not hard to do.