[LILRED66]

As mentioned in the other posts, design or poor-design, I should say, was a big contributor to the rust issues with these truck. When replacing/repairing the cab supports, cab corners, rocker panels, door skins and inner fenders, I make a concerted effort to provide additional seek holes, to ensure moisture has an escape route.

I wouldn't seal things up entirely, because moisture and dirt will find its way in and with no way out or the ability to breath, it will corrode at a rapid rate. One thing to keep in mind is that it took 30 plus years to rust to this point, so with some preventative measures, it would take another 30 plus years to rust again. I always apply a "weld-thru" primer when replacing panels that can not be accessed after the repair is complete. Also, when I open up an area prone to rust, I spray a liberal coat of rust encapsulator on the areas with surface rust, but not quite rusted through.

I have heard people filling voids with an encapsulating foam and I do not recommend doing this, because it is porous and will hold water, even though the water will not effect the foam, it will corrode the steel.

Good luck with your project and keep us posted with your progress, especially with photos of what you do.