As HIU mentioned above, the head gaskets and timing belt are good ones to ask about. The automatics sometimes have issues with solenoids going out, but if it shifts fine all the way through OD when cold, you are probably fine there. Rear springs will sag and need replaced. Rear windows tend to get balky due to rust build-up inside (factory seals didn't keep the water out very well). The head gasket issue is due to the bizarre exhaust routing cooking the head, so you're never fully in the clear unless you switch to headers or a really good wrap around the pipe. Overall, they're solid trucks, and they've given me many years of good service (I've had two stock and one modified 2nd Gens). Look it over good, drive it over the full range (in-town, highway, slow and fast, etc.), and go with your gut--if it seems shaky, walk. If not, enjoy!
