carb icing depends on atmospheric conditions, it happens in a certain humidity range and dew point temperature, it becomes a problem when the icing is internal, a fog of frost on the outside of the carb isn't uncommon, just not noticed cuz you don't usually pop the hood and look at the right time
if it wasn't affectng how the engine ran, it's not a problem .... the "modern" fix was to warm the intake air by the addition of a heat gathering shroud feeding the air cleaner, a setup found on 60's/70's GM engines
Bill
