Should still be ports on the Holley base plate for both continuous and ported vacuum. Principal difference is delivery; continuous is exactly as labelled, ported is a function of the throttle position.
You don't specifiy if your Holley has metering blocks both front and back or if the back is just a metering plate. Reason for my curiousity is that, on the manifold, at the back, between the dizzie body and the rear fuel bowl, is a vacuum port that is the typical default source for much of the vacuum demanded by various systems such as the brakes. Having the metering plate is a bit of an asset since it lets the fuel bowl sit closer to the carb body and leave a little more room to futz with the plumbing. The metering block,by contrast, pushes the bowl out about a 1/2 inch farther and it might then either cover or crash into a vacuum fitting or manifold port.
Nick