So there are a few things in this question that I think he needs help with.
One is yes most (key word) V8 cars did have 10 inch drums. But as others point out plenty can change in fifty years. So check your VIN if it is actually a V8 car. If it isn’t originally then yes you would have 9 inch drums.
Next is that the brakes seem to be missing most of the key hardware. It doesn’t matter if 9 or 10 inch drums, the mechanism will appear the same. Same parts but different sizes.(adjuster cable is different) but any photo will be ok for a reference. If you purchase the hardware and adjuster kits from Rockauto they include everything.
Lastly be cautious of what shoes you buy. There were three changes to the shoes in as many years and later shoes require you to use the later adjusters.
I have versions of all three shoes for the 10 inch and can provide photos.