Thanks, I'm having trouble finding a small enough hole saw, the studs are 7/16 I was looking for a 1/2" hole saw but the smallest I could find was 9/16. I guess I'll use that and cleanup like you mention. To be honest I can't really see the swedge on the drum I suppose it's there but difficult to see. All I know is the drums are locked on the hubs so it must be that and I certain they're factory drums. Thanks guys.
