Exactly correct. Does the plumbing go to the air cleaner?

What it does is use the negative pressure impulses to draw fresh air from the air cleaner into the exhaust stream. A "budget" smog pump system. Were it mine, I'd plug the manifolds and air cleaner and forget about it. There were factory block off plugs for the manifolds or you can fabricate something as you'll have to do for the air cleaner if you choose this route.

Robert