[68K30]

If the linkage is all good and the engine mounts are in good shape there should be about 1" of free play at the top of the travel, which translates to 1" of pedal travel without the throw-out bearing moving the pressure plate fingers. The reason for checking the engine mounts is the inner end of the Z-bar [bellcrank] is attached to the engine. If you get 1" of free play and the clutch takes hold in the upper third of it's travel the clutch is nearing the end of it's useful life; a new, properly adjusted stock type clutch will take hold [start moving the truck] in the lower third of the travel up from the floor.

Hope this helps
Bill