92 is a very late 240, so it will have better soundproofing and slightly nicer features than the earlier cars. Also airbag and ABS. It also has those horrible horrible US spec plastic headlights that yellow. If you drive at night you'll want to spend $300 on a set of cheap ecodes, and if you don't then grab some plastic polish and get rid of the yellow lenses. Lots of advice out there on that. In the midwest it will probably still have rust, see the advice above.
If it is a manual you will get high-20's to low 30's for mileage. Automatic not so great of course.
The AC rarely works on Volvos, but the 91-93 system was a big improvement and may still be working. As I recall you'll want that where you live. Clean the evap drain out every few years if the retrofit wasn't already done. Avoids water pooling up inside the box.
The heater motor will die eventually, but the job isn't really as hard as some say, and if you do it with a new ball-bearing motor you shouldn't ever have to do it again. I did mine with a standard replacement motor nearly 10 years ago and it has been just fine.
Suspension is pretty easy. McPherson struts up front and live axle rear. A spring compressor is about the only special tool required except the special tool for the rear trailing arm bushings (which are nearly always in need of replacement unless recently done). Info on homemade tools is available on brickboard and various other places, but I recommend just installing poly bushings.
Wheels for all RWD volvos from about 72-95 will fit the car. Since you have to replace the tires anyway that could be an excuse to get rid of the hubcaps.
I've never owned a NA B230 powered car, only the Turbo and V6, so I can't say how well it will go straight ahead. If you put some decent shocks on it and the swaybars off a turbo it will handle rather well. Larger IPD bars, some sport springs, poly bushings, chassis bracing and you'll have a 3000lb fridge on wheels that will corner far better than it should.
Rusty exhaust is common, but I haven't seen many NA exhaust manifolds crack. Not making stock power anyway. Regardless its easy to get to and easy to replace. 165k is barely broken in for these motors. Unless it has really been abused it should last for a long time, and even if it has parts and replacement motors are cheap and pretty easy to find. Keep oil and coolant in it, do simple tune-ups as needed, and it should last for longer than the body of the car will if you salt the roads there.
A few useful sites:
brickboard as said above is great for repair info (though I find the board hard to read)
www.turbobricks.com (forums.turbobricks.com really)
http://www.vcoa.org/ (gets you discounts on parts and service at the dealer, and a decent magazine)
Parts:
www.ipdusa.com (cheaper parts can be found, but their customer service can't be beat)
http://www.fcpgroton.com/
I have found the parts for both my Volvo 200's to be cheaper than the Mercedes parts for my sister's 240D for the most part. Not much is available at the dealer anymore beyond standard maintenance parts, but the aftermarket stuff is generally good, though the Scan-tech stuff is of spotty quality.
The Mercedes w123 and the Volvo 200 are actually pretty similar cars in my opinion. Lots of little differences, but they're both basically 70's european tanks.
And just because I never get to show it off on this forum, here's my 81:
