carb spacers???

It sounds like vapor lock. Mine was doing the same thing last summer. It is a combination of the heat, today's gas evaporates faster due to all the additives. I added a 1/2" wood spacer under my 1406. http://www.jegs.com/webapp/wcs/stor...catalogId=10002&N=4294966761+4294966876&Nty=0
It definitely helped. I also replaced the fuel pump with a new stock mechanical pump. You should heat wrap as much of the fuel lines as you can get to, make sure your tank vent is not plugged & replace the fuel filter if it has been a while. I am still fighting with this but it has got better. I may end up having to go with an electric fuel pump if I can't fix it. The Edelbrock carbs also do not like much more than 5.5-6 psi of fuel pressure but I doubt if a stock pump pushes more than that, I have not added a pressure gauge yet. Just my 2 cents, hope it helps.