when your car was new it was to activate the original nitrous system, some dumb previous owner must have hooked it up to that vent


yall never heard of the factory nitrous option?

 

my guess (going off of my 73) is a underdash vent cable? is there another side to the cable farther inder the dash that leads anywhere?

 

hahaha the first time i opened my drivers side vent i was on the highway and it had just been repaved and so a bunch of lil rocks and pebbles shot up into my legs. I actually had a few cuts and bruises and i've never opened it since. lol

 

yeah thats what it is