After seeing this lack of rocker on the drivers side I decided to open up the bondo ridden fender, just behind the cab and looked down what was supposed to be the inner rocker. This exposed the fact that the cab support rails out to the rockers were rotted as well.
So I decided to open the floor on the passenger side to expose those support rails. By doing this I was able to verify proper dimensions to fabricate new ones for all four extensions.
1979 Ford Bronco 5.8l 351M Currently Under Construction
"Boredom sets into the boring mind" - James Hetfield