Took one of our cars to track back in June 2014...made three nice runs, but after third run before shutting it off, we heard a slight "tick"...like a valve or maybe a lifter, but nothing heavy, like a rod or main. Started it again and ran at idle to listen,, oil pressure fine, but slight fluctiations...
got it home and started searching...Started it cold next morning, oil pressure shot right to 75#, ticking still there and then I moticed pressure starting to drop along with heavier knocking...long story short....must have had some detonation we didn't hear or see on scan tools, but it took out two rod bearings which lead to a rebuild.
This engine had steel shim head gaskets, so they weren't gonna give and it doesn't take much to go wrong at 24# boost with alky/93 Octane...somehow it went, BUT...BUT ..BUT, I have no compalints as this was an original factory bottom end with 123K miles and it was running 10:60's at 128...other bearings looked pretty good considering the miles and the power it was making.
Bob