Old American Standard - voids in top of cabinet

Had an old original American Standard forced air gas furnace today. Don’t seem to have the aging convention to tell the age.

I am assuming this was manufactured in August 1970… anyone care to confirm or correct me?

Model Number: GUF 80D E6

Also, there were manufactured openings on the top of the cabinet and to the sides of the draft hood. Is this okay? Since any blockage in the chimney would cause backdraft to of the hood into the garage I don’t see that the voids in the top of the cabinet are that big of a deal. Please advise if you feel differently.


Several models used to be built that way. Not an issue