[Terry M. Hunt]

All the front drums on my other cars have the drum and the hub attached to each other. The lug studs are swedged right where they pass through the drum which locks the drum and hub together. Or maybe the lug studs are splines in the area where they pass through the drum and the drum is pressed onto the hub with these splines engaging the holes in the drum. On my 66 GTO it appears somebody in the past had a machine shop use some kind of cutter to remove the swedged /splined area to separate the drum and hub. The drum now slips over the studs onto the hub the same way the rear drums slip over the studs onto the axle flange. Does this pose any safety issue? I don’t know of a way the interference fit between the hub and drum could be redone. There was very little material removed, so the drum still fits over the hub pretty snug. Anybody else seen a situation like this?

[Scarebird]

No issue - every modern car has "hat" style rotors that do the same thing.

[Goatracer1]

You probably have Chevelle drums and hubs