Cowl Vent, rust, and assorted questions?

[darrellyates]

Ok guys, I'm new here so be gentle. I have a '70 C10 that I'm building as a '68 slant nose. Any issues with sealing the vents on the inside, using POR 15 inside the airbox, and then sealing the cowl vent? The drains are open and clean. I've already put a floor in, fixed the inner kick panels, lower door pillars, rear corners, outer rockers.... You get the idea. I was following the rusty air vent thread, but didn't see the problem answer as I intend. Thoughts and advice?

Also, I have a Scott's new frame, and a new LS3 with a 4L60E, and a bunch of other new stuff to go in. Trying to it right. Cab repair is taking forever...

Thanks in advance...