Saw one that bad out of a Buick Grand National once; it had a terrible detonation problem. Cylinder wall was very bad as well. The customer knew it was having problems but drove it anyway.
Detonation came to mind to but it's naturally aspirated, fuel injected and computer controlled. This is the only cylinder that has this problem. All the rest were OK. They needed rings but the ridge was very minimal.
This project has just gotten expensive. This was just supposed to be a quicky re-ring and lifter job.
