Originally Posted by TomW
My stock '67 will hold 30 gallons of freshwater, and 17 gallons of black.
There are Airstream dealers who sell new, stock black tanks for '65 Airstreams. Maybe one of them will see this thread, and post what an original Ambassador's black tank was designed to hold. Chances are you have your Airstream's original tank.
Airstream has not had black water tanks availble for many years for 1968
and older models.
In fact, at this point, they do not have but a few tanks available for the 70's.
After market black and some gray tanks are avialable, most made with fiberglass and some with plastic.