Leafs blowing inside

Leaves fall into the cowl vent and then get pushed into the interior vents. Sometimes they get stuck in the heater or A/C box, but they can just come in through the vent boxes. If the car isn't currently being stored outside under a tree, it means the cowl is full of leaves. You can pull the vent boxes on either end and clean it out as best you can.

This is a non-AC car, but I think your '71 has all the same vent boxes. I dropped the vents and the box, reached up into the cowl, and pulled down all the stuff you see here from inside the cowl.
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vent boxes
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cowl space that's probably packed full of leaves...
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