I had a high #3 for many years and finally put a small bypass behind the cylinder so air can go around and get to the bottom fins (described in a "hot CHT #3 thread on here somewhere). Dropped the #3 by 40 degrees and all the others by 10-15 degrees. Used to be on hot days I had to climb, level to lower CHTs and then climb again, but now I can pretty much climb with impunity. I also have a Catto 3-blade set up for cruise, so it tends to heat up a bit more in the climb phase with less air going through the system.
RV-9B (Big tires) Tipup @AJZ or CYSQ