Why isnt it an upgrade? The 3.0 makes considerably more power then a 2.3, hes already got the parts, and the 2.3 is shot anyways. Why spend money rebuilding a 4 popper thwt makes 88 or so HP when with a little homework you can have an engine thats just as reliable, and makes ~50hp or so more and 65 or so more FtLbs.
Plus, its not like hes trying to swap in a 3.3L from a caravan or something, the truck is engineered to accept that engine.
Used or rebuilt 2.3l will get better MPG than 3.0l, which was the point of the 4cyl engines, and it is plug and play, same engine.
3.0l Vulcan had the nick name of 3.slow, enough said
Installing a different size engine is basically the same work regardless of the engine size.
And because VIN no longer matches engine size it may get tagged with a Salvaged title when registering it, depends on state.
If more power was the goal, not MPG, then 5.0l V8 from Explorer would be the choice, not 3.0l or even 4.0l.
Ranger can fit the 5.0l explorer V8 because they are basically the same engine bay, yes it is tight but exactly the same work is required to install the 5.0l as the 3.0l or 4.0l when it comes down to it.
And a V8 is an upgrade, for 2.3l Ranger, or 3.0l or 4.0l Ranger for that matter, lol.
If you already have a donor 3.0l then sell it to someone that needs a 3.0l engine and/or trans and other parts from a 3.0l Ranger
Then find a 5.0l Explorer with bad body
Or sell the 2.3l Ranger and buy a 3.0l Ranger with good body and bad engine and/or trans and use the current donor for that.