The information you need is found on the schematic drawings contained within the 1957 Ford Body Builder's Layout Book. I have the only copy I know of for the 1957 range of models. The pages are large and the small print measurements aren't very readable when scanned. I've been asked to make it available for creation of a pdf file or CD but would rather not do that because it could then be turned into a profit maker for somebody. I will, however, give you full size copies of the two F-750 pages. The data is readable on the full size copies. If that works for you please email me at stu_sandymcmillan at sbcglobal dot net. I'll need your name and mailing address. Stu