Unless the flight manual, or the engine operating manual provides instruction for Lean of Peak operation, I would suggest you don't. I know people who do (I suppose they can affort the cost of the engine).
I recently did an STC approval project with the new Lycoming IO-390, 210 HP engine. It's operating manual (from Lycoming as opposed to airframe related) prohibited lean of peak operation. Before you laugh that off as the engine manfacturer being conservative, it has the same legal implications as the airframe manufacturer saying that aerobatics are prohibited in a plane. It's unfortunate that often pilots do not get to see the engine operating manual.
If a worn camshaft is affecting any engine characteristic detectably - don't fly the plane at all!
Run the engine the way the manufacturer says, yes, including the fine print on the performance tables.