440 overheating at idle

It won't.
Itll just idle bad.
Does fuel cool once the blades tip, sure, but at idle.. a lean mix isnt gonna cause 220... timing hat's not advanced enough can.. a fan not big enough can... a water pump that doesnt move enough volume can....as well as a list of other things that point more to a serious problem.

The whole vapor lock heat soak crap always astounds me. I've never had that problem. Engines I've seen or heard about experiencing this condition seem to have a few things in common, usually... like tight engine compartment, low compression, less than ideal spark advance/curve, hot steel fuel lines near exh...and already run hot.

The carburetors involved are always edelbrocks/carter and Rochester, be it the mondo jet or thermo bog.
Only time i've every had true vapor lock was on an 85 Honda sabre with a V4. The engines one these always ran hot, you could get it almost boiling pulling off a highway in summer, otherwise it always seems to be a symptom of a larger issue.