I do have a question about the above comment. Personally I have operated the following GA carburated engines:
Continental, C65/C85, O200, O300, O470, O520,
Lycoming O235, O 320, O360, O435, O540, and
165 hp Franklin
I have never been able to lean any of these engines to true LOP because they all will start to run rough due to the inherent poor mixture distribution. SO I am quite interested in what engine(s) you are talking about and what technique you use to achieve smooth operation at LOP.
In my experience, some of those but not all. All the lycomings, the bigger CMI's and no idea on a franklin or a piper cub, but there is a half chance they will too.
Of course you would need to have some instrumentation and education to do it. Refer to my first post.
And I should say, Radials are better, and you must have a well maintained "conforming" engine. Otherwise you are chasing your tail, but it soon helps fix induction leaks and plug/ignition deficiencies when you do try!
I hope you are not thinking of leaving the dark side now are you?
PS: this stuff is not something that can be taught on a internet forum so I am not about to try here. As Walter Atkinson will tell you, we can't just give you a cook book with a recipe, you need to learn to cook before you become a master chef!