Dave I read this article some time ago after I first laid eyes on your beautiful cammer engine.
It appears that the secondary timing chain was a cause of concern back in the day, but the article relates that if the chain is tensioned correctly all should be well, and any chain failure could likely be tracked back to some other cause.
Ford 427 Cammer Build - 800 HP SOHC Big-Block Race Engine Assembly - Hot Rod Magazine
I hope you receive all due assistance from Keith and that you're back on the road stronger than ever in the not too distant future.