I'm trying to find the internal volume of this intake manifold plenum. But I would also like to know how to check it as an assembly, if possible? Since the velocity stacks will take up some of the internal volume.

How would one go about doing this?

I searched online, and found a few pretty lengthy processes on how to do it. But they were all decently old postings. There has to be a quicker way with far less steps. I'm using SW2015.