Leaking water inside.

It is common for the windshield and air box to start leaking on these old cars. Besides the mentioned air box problems, the seams and welds along the bottom of the windshield are pretty rough and the sealer used to seal the windshield gasket dries up after a while so they end up leaking through the open seams and between the spot welds and ends up on the front floor. It also gets between the spot welds and freezes during the winter which causes it to eventually leak more.

What I do with the cars I keep out side is take an old sign magnet used on the door of work trucks and cut it to fit over the cowl vent and cover the cowl vent every time you park it outside, this keeps the rain out as well as leaves and other derbies which clogs up the drain holes.

If it still leaks when the vent is covered, then you will need to have the windshield taken out and resealed. if you can't do it yourself, then do your home work before you have a glass company do it, most glass companies out there, have no clue what to look for or what to do so they end up trying to just fill everything with sealer or worse, urethane and end up making a mess around the windshield.