Strange situation on rear brakes - 67 Barracuda

Hey all... I have this strange problem. My 67 Barracuda has a 8.75 rear with SBP wheels to match the SBP fronts. The thing is, the rear brakes are not 9in or 10in like I would expect, but 11in. I'm not sure what the combo is but you can see that the drums appear to have been drilled and they hit the backing plates, so someone placed 2 washers on each stud for clearance. My question is... do you think I can fix this issue by putting on 9 or 10in brakes/drums and just tossing these monsters? Or maybe get some BBP axles and change out the wheels...

Thoughts?