Unique water inlet elbow?

[Tom614]

My son and I are restoring a base mode 1973 coupe with a factory 302 and it has smog control which won’t be reinstalled.  But the water inlet elbow has a vacuum port in it which I can’t seem to find a replacement. Does anyone know if this was like this from the factory or something that was aftermarket?

 

[Hemikiller]

That's the thermostatic control valve for the EGR system. It controlled the vacuum to the EGR valve, and applied vacuum to the secondary diaphragm of the automatic transmission modulator to raise the shift points when the EGR was active.

https://cdn.website.thryv.com/7fc8b09813234ba0b3c5e3c0a1b8c109/files/uploaded/73%203-11A.pdf

If you're not using the EGR system, you can replace that elbow with the standard 302 90* piece.

https://www.npdlink.com/search/products?search_terms=18599&top_parent=200001&year=1973