[nickd]

Alright, getting the message that grinding off the boss isn't a great idea. Though I'm curious why that is the case? The small amount the protrudes past the ceramic liner can't offer much for heat transfer? And I also wouldn't think that the boss adds much for valve guide structure?

Steve W- I'm not sure I understand what you mean by: the head with the crack on the boss can be repaired, but the other one needs replaced? The other photo shows cracks in the ceramic liner. According to Porsche TSB it isn't anything to worry about until a 1 square cm chunk of the liner is gone. Which is pretty substantial. These ceramic liner cracks don't look nearly as bad as photos that I've seen in other threads.

Walt at Competition Engineering seems to get a unanimous thumbs-up. I'll give them a call Monday morning. I'm leaning toward just sending the whole lot to them to check and weld/repair. At least I know where my heads have been as opposed to a tracking down a good used set.

Now what to do about the shop who originally did the work? Refund on the guide work they performed seems pretty obvious. I supplied them with guides and stem seals from Pelican, which aren't too expensive. Having CE repair and repeat the valve job is going to be much more than had the work been done right to begin with. Any ideas on an approach? Have the original shop pickup the tab that is over and above CE's normal valve job? Split the difference? One could argue that some of the blame is on me for not knowing how delicate guide replacement is on these heads and not using a Porsche shop to begin with.