A lot of guys are using the Ford 8.8 in the 1st and 2nd Gen Novas. I have not heard of anybody using them in the 3rd gen.
If you can find it in Germany I would see if you can find an 8.8 from an, I believe they start in, '96 or newer Ford Explorer. Those are Posi, 11" disc brakes, and have either 3.73 or 4.10 gears in them from the factory. They also already have pads for leaf springs.
I bought one that I was going to use in my '63 from a 2000 but, it would not work with my TCI torque arm rear suspension.
It cost me $250 which included an extra short axel so I could narrow it some more.
Hope this helps.