Eddys seem to have problems with this, they get heat soaked easy, i would run a small phonolic or wood spacer, but another area could be in the heat cross-over causeing this, i've noticed on my car, when the intake gets hot, even alittle hot too the touch, the carb is still damn near cold, its a holley with just the paper gasket, but it doesn't have the heat cross-over.

I think the biggest problem with the cross-over is not so much that the intake gets hot, its more of a "stove" or kettle affect on the carb, the heat transfering through heats the floor of the intake to vaporize the fuel, but in the proccess its heating up the carb as well, this wasn't such a major issue with cast-iron intakes, but the factory also had a heat pad between the intake/valley pan for this reason.