Today, I'm heading to look at an 8 3/4 axle housing for an A-Body with a friend. Are there specific features that can be identified to distinguish between an 8 1/4 vs 8 3/4? I believe the back of the center section between a 7 1/4 and an 8 3/4 are significantly different, but I'm not sure of differences between 8 1/4 and 8 3/4. Where is the part number located? On the shaft? Or on the outside area of the bowl where the center section attaches?