Something In my #5 Cylinder?

Thanks for that real world advice. What was the combo? Were you running boost?
N/A 360/904, worked magnum heads, 11.2:1 static compression. The KB pistons I was using are know for needing a bigger end gap on the top ring. I suspect with you running boost your rings might've been too tight or plugs too hot or a/f did something weird or a combination of it all and detonated. I gapped this next set of rings slightly larger than the KB recommended spec, hopefully no more worrying about it and gives me room for a power adder later down the road if I want. Hopefully I can finish getting it back together now the fall semester is over and I'll have time to work on things.

I'll have to make a trip down I-40 and come see your car race sometime, looks like a pretty cool build!