Thanks so much for the links! A BIG help for sure!
Any idea where the braces (ht.from floor) should be placed? Should I put one from side to side, maybe a couple diagonal ones? It seems wise to cross brace the cab as well as side to side and from front to back. I have pictures of the pickup cabs being built and they used a big jig or fixture to hold all in place whele the cab was assembled. Know that I am working on a GMC Panel.
It seems to me the floor, step, and pocket is the correct order as you need the floor in place to install the step and the step needs to be in place before the hinge pocket goes in.


1999 GMC Yukon
1957 GMC 100 Panel