Grandfather clause for heating duct to living room

[Kevin Lester]

REALLY NEED HELP!!!! I'm in the middle of closing on a new home as well as selling my current house. I went into contact with someone and they backed out the day of closing. But I completed the remedy list from the inspection. So we go back into contact with someone else and get another inspection. The guy comes up with a completely different list then the first guy. One of the items was that the duct going to a vent in the living room was too close to a floor beam. But that's how the home was built in 1979. My question is wouldn't this fall under the grandfather clause if it passed when it was built and every time up until this point? Thanks in advance for any input.