i have some lower cowl area rot! i think it was because water always sat there naturally and since i have to fix that area i was thinking of just leaving the botom of the cowl area open to drain straight down anyone have an opinion pro or con? as always appreciate any help.
thx scott:yes: oh also what are you using inside the rocker to prevent future rust, ospho or spray in antirust or something else?
thx again!!

Scott, if you are talking about the lower portion of the outer cowl, sometimes called the tulip panel, I think that there was a drain hole (or at least a formed gap) in that area on the factory car. So I don't think that leaving it open would be that big of deal. Mine was rotted away also so I'm not 100% sure of what I just told you but when I replaced the outer cowl there were provisions (or at least what I assumed were provisions) for drainage that I left open. As far as treatment of the inside of the rockers.... that will probably depend on how clean they are when you treat them. Are they rust-free or rusted are they totally clean of debris, etc? If they are rusted you will need to determine what rust treatment would work best (i.e. POR15, rust encapsulator, etc).... and that may depend on the prep of the metal that you are able to do before treatment. If it is rust-free then you have other options to consider (epoxy primer, cavity wax, etc).

The bottom of the cowl is open into the rocker. Water is supposed to drain through the vents in the upper cowl, down the cowl sides, and through the rockers, and out drain holes at the rear of the inside of the rockers covered by a rubber flap.

The problem with this design, though it does help to keep the rockers flushed out, is that leaves and crap can accumulate in the cowl sides and stop up flow into the rockers which makes the bottom of the cowls rust out.

You could leave a drain hole, but you'll still have the debris issue no matter if you leave it as designed or create a new drain. Make sure when you replace your cowl side panels that you treat the inside of the cowl well with something to prevent any slow draining water from starting the rust process.

For the inside of the rockers, if the rockers aren't rusted all the way through where you'd need to replace them, there are quarter sized access holes in the rear fender well (if original) covered by a plastic plug that you can use to insert a long wand into and spray some sort of rust prevention/converter (as mentioned by Bill). These types of wands can be bought at places like Eastwood for this purpose.

thx, yes lower cowl, i cut the front 6 inchs of the outside rocker off to get to the inner skelital structure that was rotted, the rocker it self was full of debree but was rust free except for the very front, the po had air shocks and i think that water just sat in the front rocker area witch problee never had any paint so it just went away. this car will problee never see rain unless caught in it so im leaning towards a healthy opening in the bottom of the cowl, aspho the inner then spray eastwoods antirust (wax) welder up and head to the other side.thx for the reply
scott