I have recently acquired a restored 1969 Z 28 which has developed an "knock" in the engine. I have my thoughts but before I get out the wrenches, I wondered if any experts out there could take a listen. I have not been able to locate the person who owned the car when it was restored, as the car was purchased from a young man in Albany NY, so don't have much info on the rebuild. I assume it is .30 over. I am running Leaded VP 115 octane in this engine. Thanks!

https://www.dropbox.com/s/4yrfsxz39x..._2244.MOV?dl=0

 

So, here is the answer. Pulled the correct valve cover, imagine that, and here is what I found. BTW, it sounded like a backfire thru the carb and that makes sense since this is the exhaust port. Live and learn..