Unknown vacuum line

You can read up on the 1970 N95 system at the following links & there are some diagrams included also;

http://www.hamtramck-historical.com/images/serviceHighlights/70 sh 125.jpg

http://www.hamtramck-historical.com/images/serviceHighlights/70 sh 126.jpg

http://www.hamtramck-historical.com/images/serviceHighlights/70 sh 127.jpg

http://www.hamtramck-historical.com/images/serviceHighlights/70 sh 128.jpg