Watch out for OCSMB, he may buy it and flip it.
If it's the one in the CL ad, too bad there's no interior pics. As for good deal, that's tough to answer. First and most important, it's only a good deal if it matches what you want out of a rig (furnace, stove, fridge,...). When you start making compromises, then any deal heads toward the 'just OK' side. Second, if the rig matches your needs, then next biggest factor is maintenance and condition.
For me, bottom line is that at least without firsthand knowledge, I don't see anything I'd be scared of with that rig and that price. Some people have had some issues with that generation of Ford transmission, so defintiely ask some questions there and give that some attention, and make sure 4WD engages properly, including turning the hubs on the front axle. Ask when the last oil and filter sservice was done, and what oil they're using. Also ask when the last fuel filter service was done. Good info to have, but also a test of the seller's knowldege of the rig. With my diesel, I know that stuff off the top of my head.
Oh, and for us on the forum, be sure to find out who did the 4x4 conversion and post the info back here for us to see.