Wiper Cowl Mysteries...Where's That Water Coming From?

[supplyguy]

Ventured under the wiper cowl in search of the source of water that is soaking my gas pedal area, and to maybe putz around with the non-working wipers. Found one of the two inch sized drain holes (driver side) clogged with water pooling per the first photo below. Unclogged it, but not sure how that could back up so much as to run into the cabin. Perhaps that's not the source? Lubed the hinges on the stuck heater box cover (learned what it was from this forum) and now it works. It was stuck open - presume that's why I get bad fumes in the car - oil burning off of the various surfaces being drawn right through there? Question is the grilled gizmo I can see from through the vent the same heater core you all refer to as replaceable from under the dash? Last question - what's the purpose of the two roughly 4" cylinders on both sides? They have a valve inside that is closed, and when I open it I get a nice view of my floorboard. What controls these? Appreciate any help.
PS - No luck on wipers. New motor, but not connected - harnesses do not match and no ground. Another day.

[RRoller123]

My guess is that somewhere along that drain tube that was plugged there is a crack that is letting the water drain down the firewall inside and get to your pedals area? Could probably line it or epoxy coat it when completely dried and that should stop the leak. There also could be some other point lower down where the water is leaking back in.

Regarding the big tubes either side, my 1980 doesn't have them, but they look like they are intended to provide fresh air cabin venting?