Is it under the car or out? Make sure it's the proper width for an a body. They are the most narrow and in high demand, so they bring a premium. I don't know the width off the top of my head. Does it have drums and backing plates? They are unique for an a body. How about the third member? Look on the drivers side casting numbers. Look at the last three numbers. It will most likely be a 741 in an a body. That it the least desirable because it has the smallest pinion. It could be a 742 or a 489. See if it turns freely. If it does, have a buddy hold one axle with a bar between the studs and you try and turn the other. If you can turn it, then it's not a sure grip. I looked at one just a month ago and was told it was a sure grip. Performed the test and they both turned. He was asking 350 for a 69 Super bee rear that he thought was a sure grip. No sale for me that day. Good luck. Stay warm today!