[ChevyGuy]

That's disturbing. You can try contacting Chevy Customer service here. Since this appears to be a clear case of manufacturing defect rather then wear, they might be willing to help you out.

What about a cheaper fix - perhaps a thin layer of something to seal off the sparkplug bore? JB Weld?

 

[ChevyGuy]

However, I do want to let you know. I am 99% sure they will not do assistance due to the age of the vehicle. But you can still call and ask.

In most cases, you're probably right. But Robby's message indicates differently. And he's got experience in this area.