Lean idle. Rich cruise.
The AFR gauge might not be accurate at idle. Confirm the readings before you spend a ton of time chasing your tail. Wide band sensors are very easy to fool at idle. Performance cams suck air into the exhaust which fools the wide band into a lean reading. Small header leaks will also give a lean reading. Moral of the story is that wide bands often don't read correctly at idle on "hot rods".