When to worry about engine noises?

Huh my stone stock unrebuilt 360 mag in the Durango with about 190k on it (body has more than that on it) never goes below 30 at its hottest, idling in gear at a light.
Cold at 2000 rpm, it's around 65, cruising down the road at ~1750 it's usually around 55. Something ain't right with yours