Stubby wrote:

/snip/ Nonetheless, I
would follow the manual and *if it didn't mention a specific procedure, I
wouldn't do it*.

Stubby,

That is a ridiculous statement. No where in your manual does it state
how to make a right turn in the air, or how to close the baggage door.
There are acceptable techniques for everything, some that work better
than others. I can assure you that leaning an O-320, to some degree, at
any cruise power setting, at any density altitude, will not be harmful.
At lower density altitudes, and higher power settings, you don't want
to lean *a lot*, but say 100-150 degrees ROP would not hurt a thing.

Happy Flying!
Scott Skylane