Think I have a clue about your engine failure: " After my last engine catastrophe I replaced everything including the block except the crank and rods."
Did you replace the
oil cooler? If not, there's a good chance debris from your previous catastrophe in the
oil cooler created your new catastrophe. Our practice from all engine failures, be it TransAm, Indy, stock car or whatever racing, was not to even think about cleaning out the cooler when it was involved in an engine failure, but to drive over it with a fork lift and throw it away. Otherwise the "cleaned cooler" would eventually pass debri that didn't get removed and find it's way into the new engine and result in the same story you just related.
Coolers are expensive, especially the Harrisons we trashed, but nothing compared to the expense of an engine.