Did you check to see if the boosters are spitting at idle like RapidRobert suggested?

Also, I would check the fuel pressure to make sure it's not too high (nothing above 5.5psi EVER).

When it's hot, turn it off, remove the air cleaner and look down the throats. If you see fuel pushing past anything, you have an issue somewhere.

Allegedly Holleys are slightly better in the heat soak department since the bowls are insulated with gaskets from the main body, but then you would have a holley