For another view of the leaning argument I would recommend the following reading:
Mike Busch (The Savvy Aviator) on leaning, note he has a Cessna twin and both engines are close to 100% over the recommended TBO and still going strong.
http://www.avweb.com/news/savvyaviator/savvy_aviator_59_egt_cht_and_leaning_198162-1.htmlAlso for your reading pleasure is a series of articles by John Deakin on "Where should I run my engine"
http://www.avweb.com/news/pelican/182179-1.html Part 1
http://www.avweb.com/news/pelican/182176-1.html Part 2
http://www.avweb.com/news/pelican/182583-1.html Part 3
http://www.avweb.com/news/pelican/183094-1.html Part 4
For me, I would run my engine lean-of-peak if I could, carburetor doesn't work to well lean of peak. I also don't run my CHTs higher than 380, I have a red line set on my monitor at 400.
I would also point out that the big radial engines were routinely run lean-of-peak or the airliners would not have made it across the pond (too high of fuel flow).