The Heavy, The Rare and The Weak and a couple alternatives:
So, I have been looking into doing this for s & g myself.
We'll start with the weak:
The setup you show Rick has 3 issues:
1. They are no longer made, so hard to find. And there is a reason they are no longer made...
2. When they were originally being constructed, you were buying B or C78-14 tires, which would be rough equivalent to 175 or 185/75R14s - good luck finding those at your local tire store. To accommodate more modern (wider) tires, you need to use offset rims for inside e.g. t-bird steelies: 16x6 60mm offset. Tires need at least 1" static between them so sidewalls don't touch while driving over road obstacles. (If sidewalls start rubbing you will get blow outs in no time).
3. they put a significant load on your axle: normal Ranger axle flange is ~2.5" outside the wheel bearing. Assuming 215 wide tire (8.5"), 1" space between tires (to accommodate flex when they are loaded, the center line of the outer tire is a foot (12") out from the wheel bearing, the outer edge >16". So, when you accidentally clip the curb because you forgot about the extra width, there are major forces on the poor 1.4" diameter axle.
Toyota/Datsun (they are pre-Nissan name change) class c motor homes had MAJOR issues with axles failing. To the point, Toyota recalled all their chassis and replaced the rear axle with the full float axle which franklin2 references.
Which takes us to the rare:
Toyota 1 ton dually rear differential. Note there are 2 versions of this 5 bolt and 6 bolt - you would want the 6 bolt.
Again they have a few issues.
1. While rare, there are about 1/2 dozen on market at moment per car-part. But...
2. The rims are rarer, you need 7 (you could get away with 4, but you probably want a spare and the "look" isn't right without the offset rims at the front). And the occasional rim that comes up on fleabay will set you back a pretty penny - one currently up, he is asking $170. And note the rim is 14x5 (not end of world for your 4x2 truck, not good for those with 4wd). And ideally, you want the 5x4.5 to 6x7.25" adapters to mount the dually rims on the front, and if you though the rims were rare.
3. The axle comes in 1 ratio - 4.10:1, again not big detail with 2.3 I-4 engine. But the fact that the brake drums haven't been available for 30 years is probably an issue or could be soon.
4, The Toyota axle doesn't have speed sensor for RABS/ABS/Speedo (Can't remember if that is issue for your '93; it is for my '98).
Lastly, the heavy:
Take a Dana 70 rear axle out of 1 ton, narrow it to fit under your Ranger, bolt on std 8 bolt rims and you are in business.
The issues:
1. The Dana 70 weighs ~500lbs. Heck the drums on older ones weigh almost as much as the 7.5 axle from your Ranger. Adding in 5 (4 + spare) 225/70R16 tires on steel dually rim from the 1 ton at ~100lbs apiece, and your Ranger basically has only couple hundred legal pounds left on GAWR. And the E weight range tires would have you grabbing kidney belt before taking truck out. (OK, you would probably use smaller, P-series tires as yours is 2wd, but the 40lb rim weight is a killer).
2. The brakes e.g. 13 x 3" drums mentioned above provide serious amounts more braking, so you need a proportioning valve to prevent locking rear brakes.
3. As with the Toyota axle, the Dana 70 doesn't have the speed sensor. And the big axle with its big bearings takes serious power just to turn it.
Couple other options:
5x4.5 to 8x6.5 wheel adapters*, then run the std 1 ton dually rim (OK, 8.x6.5, 16x6 rims might be getting historic now, but you know what I refer to. Note: You can find Aluminum versions of these rims which save 10+lbs/corner.) You need to stay with narrow tires to avoid contact with springs. You might want to swap to an Explorer axle - 1.605" bearing is significant strength improvement.
*I wished I could find steel ones, my faith in aluminum only goes so far.
Back in day, JC Whitney also sold rims with std bolt pattern 5x4.5 but with dually compatible back spacing. If I could find set of these, it would be ideal.
Earlier this week, I sent a request to a wheel mfr to see if they could make a set for me/cost; still awaiting response.