Head gaskets? Not on 4.3's. I can only think of maybe 2 or 3 cases in the 10 years I've been a technician at a shop. The 2.2, now that's another story, but I don't think you could get 4wd with the 2.2. The INTAKE gaskets go left and right on the 4.3, especially with the factory fill dex-cool. I recommend Peak's Global coolant. I run it in everything of my own. Ball joints, pitman arm, and idler arm routinely fail. You also have to consider the GM fuel pump plague. Don't run it low on fuel, and that will help. I've also noticed some of the transmissions with a broken sun gear shell, which causes a loss of reverse, second and fourth gears. Funny thing is that I rarely see the same thing on trucks with a v8 and the same transmission. The oil cooler lines develop leaks where the rubber lines are crimped to the aluminum ends, and CAN cause serious engine failure if not attended to. Really, there's not that much that goes wrong, I just highlighted a few things that I've seen a few times. With all that said, I DO like them. It's not often that they get towed in, unless the owner totally neglects them, and does NO maintenance.