[zoner]

John- I use the term 'magnafluxing' generically here, as in: 'make sure you check the head for cracks', but the clarification is helpful and may prevent the OP from walking into a machine shop and seeming uninformed. My car/engine experience dates from a time when most cars I dealt with were American made and aluminum heads were the exception.

As far as the sensors, I've had a couple of experiences with cars that, after overheating, temp sensors either didn't work properly or worked intermittently. After those experiences, I've just always replaced the sensors as a precautionary measure, especially if those sensors aren't particularly easy to access without removing other parts.