65 Cuda Carb and Headers...Need advice

I have a 65 Barracuda with a 273, it currently has a 2 bbl carb. I bought a 65 edlebrock intake and want to put an edlebrock carb on, however what size CFM should I use for this soon to be daily driver. 600 or 500 CFM, I have an RV cam and hi po heads. Also I want to put a set of Hooker headers 5901, they show on their web site that this will fit a 65 Plymouth 273. Any feed back or words of wisdom would be greatly appreciated.