Cap'n,
per chance did you add any internal engine cleaner and let it run and drain it before adding some more oil???
I have cleaned a lot of motors out using a motor engine flush which gets rid of all the buildups and sludge.
Afterwards, added some inexpensive oil and let it run, then drained it.
Final oil fill with good stuff PLUS some lucas products to keep those valves and lifters from chattering...
Sounds like you got it this down!
micro...