8.75 brakes

Even if you opened up the center of the original drums to fit the new axles
I don't think that will work. Because the old axles are 27 and 3/4 inches long and the new axles are 28 in Long so your drums would hang out on your shoes because of the quarter inch difference.
No the axles are correct for A body. Just the drums are wrong now. They, the axles are in the housing, fit perfect.