The "driveshaft place" would be whoever it is you were planning on taking it in to have it shortened up.
I didn't find any length charts when I searched online.
I called my local driveshaft place, and they have no chart either.
It would seem to me that if you called a salvage yard that has Hollander online, it may show the different lengths they used. Obviously, if you need one longer than a '68 Camaro, I would start by looking at cars with similar components, but with a longer wheelbase, like an Impala or Caprice???
