Was thinking about this one too... Any thoughts on how to verify this? I know the 70 318 I pulled from the car had timing marks on the passenger side of timing chain.. Used a different vibration dampener and timing chain cover with timing marks on drivers side on the 340. Is there a such thing as mismatched dampener (timing marks) and timing chain covers? If so, is there a simple way tell which is which?? Yikes! Am I confusing myself (And others)??!! Ha-ha...