It is worth the value of the brake drums on the auction site plus whatever it's worth in scrap weight. I have a few here, can't give them away. The 3.90 has very little value as well, the only one that seems to have any value is the 3.31 auto rear, minimal as well though.
According to the shop manual, the 3.91 was an option with O.D. It's more likely to be a 4.27 which is even more undesirable.
The Jalopy Journal
