47-55.1 Cab Height from Frame to Floor Pan

[richie1953]

I am rebuilding a 1953 Chevy 3100 an have found conflicting masurements for the height from frame to floor pan.
Factory Assembly Manual 1947-1954 Truck list the following: Section 1 sheet 3.09 shows the front mount measurement as 1.83+.06 -.00 from top of frame to bottom of floor pan.
Section 1 sheet 3.12shows the back measurement as .76+.06 -.0 from top of frame to bottom of floor pan. I can't get this number as the back of the body would hit the frame.
In the 1953 book from GM Heritage Center on page 127 it has a measure from top of frame to top of floor pan as 1 7/8.
Very Confusing. What are the real numbers???