How serious would you consider the damage to this chamber? Cosmetic or no? The groove you can see has sharp edges down both sides. Could this be a "hot spot" for detonation in an 11:1 motor? The mark by the valve seats looks like it was enough to warrant replacement of the seat (note how thick it is). This damage showed up as a suprise as the seller never mentioned it. What do you think? Would you use these heads? Thanks for your input.
http://img317.imageshack.us/img317/7125/1cyl45bc.jpg

It all looks very minor and cosmetic in nature. If you saw the damage to my heads after I broke a valve you would have a heart attack. Had to have one seat installed, and surfaced, but they looked pretty bad. They are still running today with no issues. Take a die grinder and a sanding roll and smooth it up. If its not leaking water, it will be fine.

If you think about it... there are more sharp edges on the spark plug itself compared to what you see there.
That would never develop into hot spot because the head itself acts as a heat sink.
But if you`re uneasy with that mark, just smooth the sharp edge over a touch and move on.

Thanks guys. I don't have a lot of experience with this stuff and that bit was making me a little nervous.