Carb heat shield . . . anyone try this?

Is it the original carb? Aftermarket? What's the model #? Is it the stock cast iron intake manifold?

Carters/Edelbrock's are known for having the bowls dry up when sitting, even just overnight. It may not be a vapor lock problem (ie, fuel getting too hot), it just has to do with the bowl vents allowing the fuel to slowly evaporate. Depending on the model of the carb, there may be a way to dial back the bowl vents a bit to keep the fuel from evaporating so easily.

And if that is the problem, the heat shield won't help you either.

The only thing is that wouldn't effect the 5-10 minute start issue, although that could be a number of things-timing, carb tuning, etc.