I've done some more work....
I resealed all around the baffles to seal joint. Also, peering at the back of the engine I noticed some swarf and other material that shouldn't have been there. I got some of it out but I need to get the bottom cowl off and loosen the baffles to clear the rest. I will also then try to get the washers in place.
Coolest cylinders are the middle, front are about 10F hotter, rear about 40F. I'm not worried about the difference. I tried going LOP for the first time and the temps dropped nicely so the hottest cylinder (6) was about 375F - I can live with that until the next time the bottom cowl comes off. I believe that removing the potentially fin-blocking material and using the washers will get me where I need to be.
Incidentally, at 10,000' using 19/2300 (50%), I was getting 150kts TAS @9.5gph
Mercy Air, White River FAWV
RV-10 ZU-IIZ - "Zeus"
Building Bearhawk Bravo - RV-18 not available
2019 Donation Made