[DeTomaso] ZF oil capacity?

[P6746 at aol.com]

I had the capacity of gear oil for a -2 ZF written down somewhere, but do  
you think I can find it now.
 
The ZF manual indicates a capacity of approximately 3.5 liters which would  
translate into 3.7 US quarts.  I changing the oil today, but was only able  
to get a little less than 2 quarts in it before it overflowed.  Seems  
unlikely that I could get an additional 1.7 quarts in it after it settled.  
 
What is the correct amount of 90# gear oil for the Pantera ZF?
 
Sorry to be a pest.
 
Bob Reid