I used this
thread to get some bearings on how to approach the project. The key I found was lining up the rocker to the door, cab corner and fender. This took a lot of trial and error along with grinding and hammering the rocker. Once installed, rocker just laid on top of the posts on either vertical end. I took the opportunity to practice my welding by building up the weld and then grinding them down to look flush (Pics 3&4 of post#9). It was either weld and grind or use body filler later, so I chose steel
.
The link above will likely give you better reference points. Good luck!