Hi,



I pulled my #1 plug from my stroked 340. I have not learned the art of reading plugs. The porcelain appears to have chipped off on one side of the plug. I think that is indicative of detonation; but I haven't heard any rattle or ping (means nothing). The plugs are Autolite 64's.

https://drive.google.com/file/d/15R7gOsiHDfcLlziLcsJYAa1f0qF0jXW8/view?usp=sharing

https://drive.google.com/file/d/15X6JF_Ls3pw8PNM9XuHqk_3mki3e09HF/view?usp=sharing

https://drive.google.com/file/d/15WXBwJnwwYXbtvrHfXDCLO8ZvD7N-2rm/view?usp=sharing

TYiA!