Trying to identify an engine part

[Steeveedee]

Note that you should use straight pipe plugs, if you haven't found that out already. The tube fittings are not tapered. If you really want to not be concerned about a "violation", just swap out that exhaust manifold for one without the fitting provisions.

The A.I.R (Air Injection Reactor) pump was used to provide air into the exhaust until the engine warmed up, to help combust the rich mixture during warm up. Once the thermal vacuum switch (TVS) closed when the engine was warmed up, the pump no longer sent air into the exhaust. Keeping it "legal" would also involve removing the TVS, as that would be further evidence that the A.I.R. system had been present and removed.

Back in those days, I was a California State licensed smog tech.