[Handy_Cruiser]

You likely will not know until you take the head to a machine shop to be checked out and rebuilt. I recently did a Mazda 6 head that was almost as bad as you describe and it cleaned up perfectly.

Normally, a machine shop will check the head first. And if it is bad, they will just charge for checking it out. And that's usually not too much. Take the valve seals from the new head gasket set with you to the machine shop. That will likely save you the cost of the shop having to go find and buy them.

Also, you will need to flush both the intake and exhaust manifold to get the antifreeze out of them. Burnt antifreeze can also stop up a catylitic converter. Check the deck on the block to assure there is no etching or pitting. And clean any antifreeze out of the cylinders out NOW to help avoid rust pitting. Coat the cylinders and engine deck with oil. It can be removed later before you install the new head gasket. I would also drain the oil pan.