This sounds more like a question for the Cessna Pilots Association forums.
A few years back I had an annual and my CHTs went through the roof. Turned out they had changed the ignition cables, which for some reason made things run hotter. But the baffling was in poor shape. They fixed the baffling and things were fine - in other words two unrelated old-age issues were cancelling each other out, at least as far as the CHTs were concerned.
I would definitely get the baffling looked at.