I got this truck from my sister for free because it needed a new engine. She inherited it from our parents (who bought it in '87) because it needed a clutch. After replacing the engine (and now the transmission), I can turn my attention to other things.
My sister named the truck "Moose" because it'll go anywhere if it wants to, just not quickly!
The amount of maintenance this truck needs is to be expected, given the age and mileage (and the abuse it took before I got it!). Once I'm done, the truck should last indefinitely. The body has less rust than most, but the work there is dents (see: abuse). My only structural concern is the front cab mounts, which rust out on most older trucks and virtually all imports. I would like to make this thing last long enough to qualify for "collector" plates - another seven years where I live.
I have found the truck to be surprisingly capable off-road. With the addition of 30-inch tires, I can keep up with most of the guys in my club. The low gearing is great in mud, even though it reduces road speed. I get a lot of vibration from my tires, so I'll probably replace the steering damper (stock on this truck!) with an after-market one. I'm also going to install a cooler for the power steering fluid, as I find that the pump tends to warm up quite a bit and old fluid has a distinct burnt smell.
The truck is actually better in the rough stuff than on the road. The aforementioned vibration, in addition to the inadequate soundproofing, make this a noisy truck. The sound inside the cab doesn't hinder conversation, however. As I mentioned above, I replaced the insulation, but it didn't make a huge difference. Coincidentally, the cab has the original black carpet. It looked rough until it was removed and shampooed, now it's like new! I would like to insulate the hood liner and firewall, but the later will be tough with the engine in place since ther is only about 2" of clearance and you need that to access the upper bellhousing bolts. Unlike a previous reviewer mentioned, my 5th gear does get a lot of use, especially on long descents. This likely has more to do with the rebuilt Z24 however.
Compression braking is quite effective on this truck, especially in 4-wheel. I once crawled down a 30-45 degree creek wash full of loose gravel and med-large, rounded rocks. In 4-lo and 2nd gear, I didn't have to touch the brakes for the whole 3 km down. The truck was moving at walking speed all the way. Indeed, it would have been VERY treacherous to walk down at all. The only drawback to bear in mind is that clutches are a lot more time and $$$ to replace!!
This summer the truck will be towing an 800 to 1000-lb trailer on highway and gravel roads, but I'm not too concerned about the truck's ability to do it.
Another appealing feature of the truck's layout is the divorced transfer case. The lack of a fixed connection between the transmission and transfer case makes an engine/tranny swap an easy proposition. You retain all of the original running gear from the transfer case back. I personally have seen a Buick 3.8 installed with an auto trans and I've heard of a Ford 302 swap. I would question whether or not the drivetrain would stand up to the V8 and the front suspension's ability to deal with the weight.
My only other non-maintenance related issue was with the seats. The stock seats appear to have been designed with DIScomfort in mind. I replaced mine with those from a 94 Dodge Shadow 2-dr and it made a world of difference. The required modification was well worth it.
In summary, this truck is great if you can do the routine maintenance yourself. Remember, though, that the truck was never intended to pull a loaded 5th wheel through the mountains! As a fun drive for which cheap used parts are abundant, it fits the bill perfectly. One of the best things about offroading this truck is that dents and scratches are "character marks"!