'75 A model 8.25 worth upgrading or leave as is?

Thanks forphorty.
I have searched and came up with the same result too.Considering that I bought the complete diff for only $85 and for the 4 1/2 bc.I just wanted to freshen it up before it gets installed in to the car.

Can I at least change the ring and pinion? According to the '69's original ratio. It is lower than the '75 2.45.
There is no tag on 69's diff,but upon my research it say's that it would probably have a 2.73 or 2.95 ratio.I would be fine with that.