I've just read some notes that say leaning of mixture should not be carried out with more than 75% power set - like in the climb I suppose.
Lycoming says "Use full rich mixture during take-off or climb." Elsewhere, the instruction was not to lean at more than 75% power without appropriate instrumentation, which is rather more permissive.
If you have an engine analyzer (and you trust its readings) I can't see any reason to avoid leaning in the climb entirely. Unless your injectors are so well balanced as to permit lean-of-peak operations at high power, it makes sense to stay well on the rich side of peak EGT. You can then use the CHT as the parameter against which you lean. If the CHT rises above target (somewhere in the 380 - 400 degF range), then you either need to enrichen the mixture or increase the airspeed to bring the CHT down.