I just went out and remeasured. I used the back edge of the stake pocket (your point A) - see the attached pic. There may be some differences in the flange width of the aftermarket stake pockets, but my stake pocket is original and didn't change position. There's a notch on the rear of the bedside that matches up to the back of the rear cross-sill and I believe lumbersawyer's measurement would be to the back of the rear cross-sill which is a bit forward of the rear of the box, and equivalent to your point C. I would use that notch as your starting point with lumbersawyer's measurement, which shoudl bet you in the right location. Hopefully that's clear enough.
Kevin 1951 Chevy 3100 work truck Follow this saga in Project Journal Photos 1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car) Busting rust since the mid-60's If you're smart enough to take it apart, you darn well better be smart enough to put it back together.
