Check out this Technical Service Bulletin.
Very cool find! Thanks! So from that, what he has is a factory hot idle compensator PORT and not a valve.Check out this Technical Service Bulletin.
Ok. That mystery is now finally solved. I have been reading those TSBs but never the 1973 part.Check out this Technical Service Bulletin.
That's why a thought that it was added later. I never knew that hic-PORTs without a valve even existed. Since thisTQ obviously is remanufactured it's not sure that the parts were originally together. Now I know how to deal with it.If it had the valve, it would have the two threaded mounting holes, as seen in post #48.