Not for certain....could be a Sure Grip...I have a 7 1/4 SG in my Valiant. If it doesn't have the tag on the diff, easy way to tell is to put it up on stands, turn one wheel by hand and see if the other wheel turns in the same direction or the opposite direction. There could be a "False positive" due to something in the rear, but short of opening it up, that's a method.
There are several threads in here about it.
