Blue,
I will be jumping into the same pit very soon. I will be replacing my entire floor pan, outer rockers, and cab corners too. I have a plan and I will be sharing it during the holidays on the project journals hopefully. Measure everything once, twice, thrice and jot down these measurements. Then measure once, twice, thrice again to be sure you've got them correct.
Then before cutting anything...do your doors fit? Take this into consideration when measuring and before cutting.

Then BRACE the cab in every direction. My AD truck driver door doesn't line up perfectly because of this glaring omission. It is close but still bothers me despite hours of massaging and attempting to fix without starting over. Oh well, the c10 I will be starting soon won't have the same mistakes.

I think it would be easier for me to locate a new cab as well, but then the truck wouldn't be Grandpa's truck anymore. The old girl has been through a lot so I won't give up on her yet. 😉

Last edited by Fox; 12/05/2017 6:01 AM.

1970 Chevrolet C10
Grandpa's -- My first truck -- In progress to shiny
Follow the build in the Project Journal
1950 Chevrolet 1-Ton Dually
"Ole Red Girl"
In the Stovebolt Gallery
More pictures here
1951 GMC 9430 1 ton dually--Shiny! | 1972 Chevrolet C20- Rusty- the puzzle box lid for the C10 | 1962 AMC Rambler American- my wife's
Parts trucks-
1951 GMC 9300 | 1951-GMC 9430 | 1951- Chevrolet 1300