Yes, your head is probably toast after overheating twice. The symptoms seem to support this. I got tired of changing head gaskets, and finally realized/admitted that the head on my 2.6 was bad. I went with the AMC head, and haven't had a problem since. The link to buy AMC heads is shown in the previous post. I found them easy to deal with. I bought the head with new valves already installed.

It takes me more than a weekend to change a head and gasket, but I'm slow at this stuff. If you do it yourself, just go slowly, take notes and pictures so you can get it back together. I use lots of sandwich bags too, and airline luggage tags to label things.

Take a look at the pictures I've linked below.