Dart SBC 8-3/4" rear axle dia vs Yukon

I got a '69 Dart and it came with a 8-3/4" housing in the trunk and a set of stock axles and a set of new Yukon axles. I thought that the Yukon axles were a lot thicker but they are the exact same diameter as the stock axles. Does this look right or could these be C body axles cut down and resplined? I wouldnt' mind running the stock ones so I have the SBC and just selling the Yukon axles. Also, will the stock 7.25/8.25 backing plates and drums work on an 8 3/4"

So long story short I guess what diameter is a stock a-body axle?