Hello, I found a 8 3/4 locally; although I am not familiar with them.
Heres ad:
I have a rear end out of a 67 belvedere, it is a 8 3/4, not froze up. not a posi or L/S it is a open spool with 2. something gears in it,good rear end. $150.00, It is a 489 cas. thanks paul, duster/dart parts...