Ever seen one of these? Electro nox box?

[John Larkin]

I was at a customer's shop Wednesday. He buys and sells cars randomly depending on if they are interesting to him. This one was a '70 GS Skylark, original paint, medium blue with white bench, 350 engine. He popped the hood for me: the car is tired, paint worn, engine dirty but overall unmolested. As he was closing the hood, I stopped him as I noticed this box on the right inner fender. I have never seen anything like it in my life and have not found anything on the 'net about it either. Tell me if you all know much about it. It has a vacuum hose running over toward the distributor but I did not have time to check closely. Very interesting though. Car was from Texas but spent most of its life in California.

 

[novaderrik]

someone asked about one of those on another forum a while back... basically, it was an aftermarket doodad that retarded the timing or something to lower the levels of smog forming NOx emissions on cars that didn't have egr valves. i think a few states tried to force older cars to meet the current regulations back in the early 70's, and this was one of the aftermarket ways of doing it.