I guess the question is what your goal is.
I must admit that I have a FORD, but managed to bump into the Chevy forum. Hopefully I won't be banished.
I happen to be one that will push the limits of my pickup, and so far it has done ok, although not very FAST.
What I discovered is that all tires aren't created equal.
I'm trying to remember my tire sizes.
205/70R14 - Wt Rating, approx 1521 - My snow tires, got very squirrely, couldn't handle the load.
215/70R14 - Wt Rating, approx 1554 - I think these were stock. Barely handled the load.
225/70R14 - Wt Rating, approx 1675 - I think these are what I put on the pickup. Did great carrying my CitiCar/ComutaCar.
So, 100 or 200 lbs / tire (multiplied by 2 for rear) makes a HUGE difference in the handling of the vehicle.
I'm not big on having tires sticking out the sides of the vehicles, but there could certainly be advantages of dual tires. I suppose it would take a lot of work to make a dually setup to fit entirely under the bed that was the same width as the stock tires.
I bumped into this on E-Bay today.
Datsun Dually Rear End - $200 + Shipping.
From what I'm seeing, it might be worth it for just the rims, but for your purposes, it might also give you a good differential, and all you would have to do is figure how to get everything attached.
I haven't seen 14" Dually Rims, but, I did see 14.5 Dually Rims and 15" Dually Rims for sale. The second listing (15") is from a Dodge Sprinter. I assume it is a commercial rear-end from a commercial vehicle. I'm not sure of the width of the rear-end, but you would probably want to have it cut down. You could use low-profile tires to match your stock tire diameter.
I'm pretty sure you can cut down a rear-end as I think that was done to my brother's 327 Ford Capri many years ago.
There is a similar question in a different forum listing a conversion "kit" for 2 Grand.