The Stovebolt Site Forums The Shop Area Engine Shop How can identify the size of my holley 2brl carb??

I am rebuilding a GMC 302, and will keep it stock with one exception. I am building custom tubular headers, and duel exhaust. The carb that was on the motor is a holley 2 barrel. I was thinking of looking for a Mcgurk or CLifford triple carb intake setup. If I go this route, what size carbs should I be looking for? Or, should I go with a single carb, 4 barrel say 500- 600 CFM??