Timing chain slap/rattle. Pay close attention to the front end sounds on startup. And no, it's not just that the "valves need to be adjusted". At this point, most 22re 1st gens will either already had them done, or they're due (not a maintenance item but the guides often break, especially north of 150k miles). See if it's been done. Ideally, pull the valve cover (a few minutes) and shine a flashlight down the front to look for a broken guide. That'll also give you chance to see the condition of oil (sludge, etc.).
Front axle seals. Weeping birfs.
Check the normal stuff you do for every vehicle (search, been covered everywhere).
Overall, remember you're buying a ~25-30 year old truck. It won't be perfect. But if it's been maintained it'll still be solid.
Maintenance records, maintenance, maintenance, and more maintenance :bash:
You can always post here to get our opinions on specific rigs. BE PATIENT and don't form an emotional attachment to any particular rig!
Good luck bro.