Yes, I saw an old 4-banger turbodiesel Ranger in a junkyard. I think they made something like 55hp though, probably not the best contender for being a Mustang killer.
If you want a quick unique Ranger that's reasonably fuel efficient and diesel isn't an absolute must, they were available with a 2.3 liter 4-banger. Ford made a turbocharged version of that engine for the Mustang SVO, Merkur XR4Ti, and Thunderbird Turbo Coupe. It put out around 190hp/240tq stock, and is VERY easy to reliably increase from there. A lot of people drop the turbo engine (it bolts right up to your existing mounts and tranny) and computer into a 4-cyl Ranger and end up with a nice sleeper. Check out
www.turboford.org for more info.