I assume that you are now using CHT probes that attach to the CHT boss---and that they are the ones the Engine Monitor manufacturer recommends.
470 is way too hot for cruise. You did not say how hot the other ones were. If the other ones are way too cold, then it is a simple matter of stealing some flow from the way too cool ones and redirecting to the way too hot one. If you can't spare trading some heat (raising the temps of the others to bring down the hot one), then you probably have a lot of air leaks.
Assuming that you have a standard size NACA inlet duct and a fairly normal exit opening, you may have problems with your baffles. You need to make sure everything seals. Look around the cylinders--all the air should channel thru the fins. If the metal baffles are pulling away, then you need to fix it. There is a lot of reading material that shows how much of the cylinder needs to be covered (entrance and exit openings). Wait until after dark to look at the baffle sealing. Put a light under the cowl and look for light leaks---fix all those problems. Do it with both cowls on----and then one at a time. Check around the alternator and starter (and of course if you have downdraft, you don't have to check around the alternator and starter----

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Also pay attention to any wiring, ducting, etc that you have running underneath the cylinders. If you have a lot of junk in the way, air is going to have a hard time making it through any rats nest you may have down there.