i have a holley carb that i just got used for free. its a 600cfm vacume secondary, non double pumper with electric choke. i only see one large vacume port that i assume you would have to use that for the brakes unless you went directly from the manifold. is that for brakes or the pcv valve? if it is for brakes, where is the pcv valve port? is that a small one?

 

I would run the PCV into the carb on the large port your talking about and the brakes straight off the manifold.

 

Run both off the same port, just add a "T" in there somewhere. Thats what I did, and it works fine.