If it's still cruising rich, it may be the IFR's.
How many turns out are the idle mixture screws. If less than 1.5, it may need smaller IFR's.
Jets do not always control cruise speed fuel in the system. With the AFR, you can figure out when the jets start to feed the engine. Watch it on a flat road and run 2K and up 250 rpm steps and note any change to the AFR. Once it starts to go richer, that's where the jets are likely activating.
This way you can tune the appropriate circuit.
