I've got an 02 Sport so I'm normally at the 3rd Gen area, so thanks for letting me visit.

Saw a 91 with 158k on the clock, with a bad headgasket. 5 Speed. I've got a friend who does all my mechanic work for me (retired certified mechanic) so he could do the HG and he'd charge me $40 an hour for labor.

Thinking of this car for my recently married son.

Now, no flaming please as 2nd Gen's aren't my thing, but with that HG fixed, is this a reliable rig? Like the V6 can go forever like the 3rd Gen? All things being equal of course.

Thanks.

With a new HG, the V6 should be quite reliable. Lots of them go 200-300K miles. That being said, what's your son's use model. I don't think the 2nd gen 4runners are the best for daily drivers any more. Not much in the way of safety features (no air bags, limited or no ABS, lack of side crash protection, narrower track thus easier to roll over, etc.) Also not enough room in the rear seat for car seats for kids, if the newly-weds get to that point soon. Plus, even well tuned up the power is not impressive, particularly at freeway speeds.

As a fun and capable offroad vehicle it's great, but look for something more modern as a DD.

hopefully your son would not need to count on good mileage.
i wish mine had air bags like a 3rd gen

The 3.0 isn't nearly as reliable as a 3.4 so make sure it's priced accordingly. They will go forever but they'll be running on 3.5 cylinder's worth of compression and guzzling gas like a V8 if you don't keep up on valves. 158k is likely low enough mileage that a valve hasn't burned yet like they always do, but if you're pulling the heads get a valve job done anyway (and check for leakage with compressed air and naptha before you bolt on after). Have your friend adjust valves and err on the high side of clearances and they'd be good for a while. For a 29 year old rig you won't find many that are more reliable but it's still 29 years old. I'm rehabbing my '90 (and logged on to talk about how I'm modifying it for safety) so they do have a spot in my heart.

Like has been said, think about the usage, for safety, power, and speed.

We're in the mountains now, getting 300" of snow on an average year. I've never got stuck in my '92, and it does fairly well even going up and over 8900' at highway speeds. I don't worry about a little salt or digs in the winter, and feel great about it driving around town.

OTOH, without airbags it's a safety worry on the highway, though technically no worse than it used to be when no one had air bags. Without traction control, there was one time I fishtailed 5 times at the top of the mountain before recovering. Scary stuff that made me buy a 3rd get to at least have an airbag, but then that commute ended and I preferred the old 4runner. In our snowy area I've seen a suburban, subaru, and audi on their lids (along with a 4runner and 2 other cars, all in the first 2 weeks of wintertime commuting). Personally, I'm not as worried about the narrowness, nor too much about a side impact.

Mines only at 179k, with the V6 rebuild back at around 75k. I've owned it for 15 years and about 100k, and the only engine breakdown was the starter needing replacement. Otherwise it's been good too, replacing the rear window relay and motor, plus standard stuff like front shocks, battery, plugs, cap/rotor, wires, cat/muffler/pipe, and then the fan and a power steering line when the plastic fan exploded. And just had to replace both presumably original CV axles, after one inner and one outer boot went.

But I did just have a check engine light come on, hopefully just the O2 sensor.

All in all, they are very reliable. It's time to do a few more things, like timing belt, other belts and hoses, and plugs. And I just ordered replacement springs for it's saggy rear end. But overall, it has been great, with my only hesitation being on the safety features and it's age.

The 3.0 mechanically is a remarkably reliable engine. Some guys have head gasket problems, and it is somewhat a design issue, but this engine will last a long time but it needs to be maintained and well taken care of.
If you want big tires, a lift, and then rock crawl and tow a trailer up mountain passes, and floor it at every stoplight because it's too slow, then you'll end up ruining it.

Mine has over 300k miles and got 22 MPG on my last highway trip. I drive it on several thousand mile long road trips, on and offroad, without hesitation.

Maintenance on an old vehicle means more than just oil changes I'm afraid. If I wasn't doing my own wrenching I wouldn't own a car this old. But I've been taking care of my own cars my whole life so I am comfortable with it.

For the side impact thing, get a set of rock sliders welded in. Not much you can do about airbags though.

Good luck!