Try some dielectric grease inside of your plug boots, you said you just installed the motor, it sounds like you might have the distributor installed incorrectly, therefore your timing might be off. I would look at the ignition system before messing around with the carb, you said its runnning rich so I would believe its not firing properly. Most Edlelbrock carbs run perfectly right out of the box, but if you find the ignition system operationg properly just give Edelbrock tech a call they can probably help you out. hope I pointed you in the right direction.