Do you have the pre-heater duct from the exhaust manifold hooked up? This is where swapping a carb can be tricky. It will need the thermal switches on the intake manifold connected up to a viable vacuum source and have the vacuum servo on the intake duct operational. The heated air from the exhaust manifold should solve the running rich issue, so that piece of corrugated tube has to be installed between the exhaust manifold and the intake.