Four driveshafts, and all close enough to take a trip to get another, come back, and install it? Major envy.
Out of curiosity, was it the right length, or was it longer than the one that self-destructed? If all your driveshafts were A-body spares, I can't imagine anything that would be longer than a shaft for a Dart with the 111" wheelbase, smaller 904 transmission, and the tiny 7-1/4" differential.
-Kurt