Just some follow-up. Passed 40hrs recently. Same cooling setup. I tested with and without my inlet seals, then with and without duct tape in there place. I don't have a manometer setup, so I cant accurately quantify the results. Based on general observations, I would say the duct tape provided the best cooling flow, but only very slightly if any over my original setup. Without any gap seal was noticable, probably worth almost 10 degrees on climbout.
At this point I am back to my intial setup, It appears the engine just needed some more break in time. Temps have dropped quite a bit. In climb, 1&3 are still my hotter cylinders. I will still work to improve cooling, but it is acceptable now. EGT sensors are still entirely unreliable. Even with new proper thermocouple connectors. I am going to pull them all at the next oil change and play with the wiring.
Note, on this flight I did not have my nose wheel pant or leg fairing installed (finishing paint).
Power pulled back, temps even
Wide open, you can see 2&4 are good, 1&3 are a little hot. But much better thsn before.