Catastrophic Failure of the Camshaft Bearings

From what I saw on "Fast & Loud", they didn't use a break-in oil with the zinc additive already mixed in as part of the formula for that particular oil. They instead used regular oil and added a zinc product, and the 302 ci in the Shelby crapped out right after they started it. They drained the oil and it was full of metal shavings. Apparently it's pretty critical on these flat tappet cam engines to use the proper oil, or you'll be pulling the engine and doing another rebuild like I just went through.
I'm no expert, just articulating what I've heard and seen recently.