Does it matter where the PCV vacuum is taken from?

I assume it needs to be a full vacuum.

My current one is on a T with the trans line, from the manifold.

Should I look to move it to a dedicated port on the carb?

Yes, I would. You want your brakes running off of manifold vacuum. You should have a port right behind the carb on your intake. Then run your pcv off of the carb with constant vacuum. It should be on the base of the carb pulling vacuum from under the butterflies.

pcv normally connects to the big port on the front of the base of the carb.