It covered everything. I did not expect this with Castrol. I've changed cams, intakes, and heads and have never seen varnishing to that degree. That's my opinion. I think that wether you cruise or race its the only way to go.
Technology is the way to go.
I built a 400 SB for my friend. He is religous about changing oil, the engine was well tuned with a new edlebrock carb, and the truck was driven all year. At 25,000 miles a cam lobe wiped. I was shocked at disassembly because of the oil varnish coating throughout the engine. It covered everything.