[dsraven]

some guys delete the vent panel in front of the windshield because they won't be using the floor vents and will be using recycled cabin air if the heater/ac is used. that way leaves, pine needles and water can't get into that space and cause rust again. some are also using a different drain set up at the bottom of the side cowl panels because the stock metal flap at the bottom tended to be too small to let anything through if needles or leaves did get in there. then the cowl filled with water and drained out onto the cab floor, which is what caused a lot of floors and hinge pillars to rust out badly.
do you plan to use the stock vents and heater etc? I repaired mine but may cover the vents with some screw on covers in case I need to get back in there at some point. my configuration is different than stock as I am using a donor frame and partial floor pan along with the heater a/c unit from the donor.