Should be a 3.23 if it is a center drop out round back 8 3/4 rear end.
A 8 1/4 or 9 1/4 rear end with a removable back cover will have 3.21 gear.
Anyways a 8 3/4 489 case 3.23 with sure grip is a good deal for $250 alone. Now sell whats left of the rear end for $200 or trade with someone a C-body rear plus $125-$150 cash to you.
Did the rear you get have backing plates for the drum brakes? Did it have the U-bolt plates?
