I like to use this carb base gasket:
Edelbrock Heat Insulator Gasket
First get the timing dialed in... Start around 10° - 15° advance and see how it runs...
then dial in the carb next...
That cam should idle at 700 - 800 RPM ... Something is not right...
Also check to make sure that you haven't mixed the #5 and #7 wires on the distributor...