I was tearing my head down because I found a burnt valve. I discovered that I have a crack in one of my exhaust valve seats. The exhaust valve right next to the craked one (to the right) was the one with the burnt valve, but that seat is okay.

Is something like this common and is it repairable, or is this head trashed? I'm in a bit of a pickle now because I just ordered new valves. This is the OHC-6 1BBL.