Then what I did was mount the outer rocker using sheet metal screws to where I needed it to be for acceptable gaps. Because the cab corner needed to be apart of the solution I had to temp install it as well. This corner had been replaced once before so I have to use the whole patch panel. Note to self have the patch panel in had before you cut out the old metal. Doh!
I will have to weld in a small strip of metal to fill the gap. I got the gaps to where I am happy with them. This isn't to be a show truck so "good enough" is really good enough. I will now have to weld in a new inner rocker so the outer will sit nicely on it.