Your engine was one of the cleanest inside I have seen. You are clearly staying on top of those high dollar oil changes. Looked brand new inside.
Yeah... Running additional HP over stock, I don't want to stick to the factory 15K per change. I do it about twice as often, sometimes a little more often than than. The Methanol injection helps to clean it too.
"Praise be to our prophet, John Moses Browning, who hath bestowed upon us the new testament of shooting. Delivered unto us, his disciples, on 29 March 1911 A.D."