Just from what I'm reading, I think you may have the Free Travel of the pedal mixed up with total pedal travel. The Free Travel measurement shown in the manual is just the amout of distance the pedal will move before it begins to disengage the clutch. If the pedal won't go any further than the Free Travel, it could mean that the clutch is stuck due to rust. One way to check would be to remove the transmission cover from the floor pan (which will give you better access to both the trans and the clutch rod), then remove the pentagon shaped cover from the top of the bellhousing. This will give you a good veiw of the clutch operation without having to get under the truck. I can put up a pic of mine if you need to see what I'm talking about, even though mines a '55 2nd, it is similar.
