[Camarowguy]

I'm still sticking to my original theory of not having enough piston to valve clearance. The ls3 engines have no valve reliefs. So cam selection is important. And just because the same cam worked in your buddies car doesn't mean it'll be ok in yours. I learned that lesson building a 4 wheeler engine. I'm imagining that your shop, huggerorange, has installed this same cam and had no issues. So valve clearance wasn't actually checked and here you are left holding the bag. Why did it take so long? Well my guess is you had less than the minimum clearance required and when you ran the car hard you had ever so slight contact. Then the springs got some miles on them. Things got worse. And then you know the rest of the story.

I don't own a shop. I've build lots of engines though. From go-kart to lawn mower to atv to stock automobile engines to the pretty powerful engine in my former third gen. I had failures. I've learned from my mistakes. I now know what it takes to build a reliable engine. The most important thing is to check, check and recheck your clearances. I'm anxious to see if you cam pin broke and caused this. If that happened, well I could be wrong or the above I mentioned happened and help push that along. I guess we shall see.