So I pulled off the driver side valve cover and had to scrape whatever I could out from the head, it was layers on layers. I change my oil every 7 to 8k miles with full synthetic. I'm gonna open up the passenger side tomorrow and see, if its bad its probably everywhere. I cleaned my oil pan when I replaced my pan gasket chasing an oil leak, I'll probably do the UV trick eventually. but what would you guys do shorten the oil & filter interval?