Thanks for the info! I have some used Rangers off Craigslist that I am checking on if they will ever respond. I'll let you know what happens.It's been talked about a couple of times. I think the biggest obstacle was a transmission. The only rear wheel drive application is the Ranger. That being said, other than automatics, Rangers and Mustangs never shared the same transmission.
Much like the guy who grafted an SHO V6 into a Fox Mustang, an adapter or motor plate would need to be fabricated to mate the Duratec / Zetec to a RWD manual gearbox (T5 or if you're really froggy, a nice 6 spd). The rest of the job would just be making all of the Duratec support hardware fit somewhere in the Fox engine compartment.
There's more, like instrumentation that add tasks to the "to do" list, but really nothing that can't be overcome with some good thinkin'