It's definitely not an OCI issue... the engine has at most 15k miles on it in 3ish years and I changed the oil once when I pulled it out of the garage after the winter, middle of the summer, and again when it went into storage.
I drove it to work most of the time, 3 track passes, 2 dyno pulls on a small tune, most of the miles on it were to and from Morgan's shop getting more stuff done to it. I did nothing but spend money on the truck replacing many parts out of caution and the only reason I decided to sell it because at the time it was the first time the truck was in good enough running shape I felt comfortable doing so.