I had problems with fuel pressure above 5.5lbs, try setting your regulator lower as suggested above and reset your floats (mine were out of adjustment from too high pressure). Also, have you checked for a vacuum leak?, a vacuum leak can make the metering circuit too rich.

Some helpful info;
http://www.edelbrock.com/automotive/...ers-manual.pdf

And here (read at the bottom of the page, TECH TIP: Is my carb too big or small?);
Quick Fuel Carburetor Size and Series Chart