I don't think there are any AM stations at #1 in any sizable market I can think of, except for WLW. It wasn't that long ago that KMOX St. Louis, KDKA Pittsburgh and WCCO Minneapolis were consistently #1. WSB Atlanta was too, but Cox gave it an FM simulcast in 2010.
It's true, iHeart has not given any of its heritage AM stations an FM simulcast in recent years. In the 2010s it had begun the process, giving FM simulcasts to KOGO San Diego, WVOC Columbia and KNST Tucson. A few years later, it reversed those moves to restore FM music formats.
In a few places, iHeart FM simulcasts have stuck, such as WGY Schenectady-Albany and WSYR Syracuse. In some Southern markets, I guess where conservative talk radio is most popular, iHeart puts talk formats on a few FMs, including Birmingham, Raleigh, Greensboro, New Orleans and Charleston. And iHeart has two Hot Talk FMs in Florida, WTKS Orlando and WZZR West Palm Beach. But with 866 stations in 150 markets, very few are iHeart talk stations on the FM dial.