Every guy out there wants more power! LOL
Unfortunately my power hungry friend it might be easier to buy another Ranger with a 4.0l.
I don't know what would be entailed exactly.....But there are wiring harness problems, computer, engine mounts and I am not sure about bolt patterns from engine to transmissions???
It was right around the end of the 90's that Ford went to returnless fuel systems as well (this meaning that a lot vehicles had a feed fuel line and a return fuel line. on a returnless system you only have one fuel line feeding the engine.)
It's not to say that it couldnt be done but it may be more work AND expense than you bargained for.
Sorry to be the bearer of bad news.....If someone hasn't already broke the bad news to you