While working on engines of all kinds, I've noticed that cars that adhere to the manufacturer-recommended oil changes for too long tend to have value stem seal problems. I've seen engines with over 200k miles on the clock that had oil changes every 6,000 miles and the cylinder heads, cams, and springs still looked brand new. If the seals appear scorched, as in the picture, I'd be surprised if the rest of the head running gear looked the same.