11 inch drums on a 72?

[aquastang]

I need to do a brake job on my 72 coupe (302 motor, drum brakes, no power). When I pulled one of the rear drums off it appears to be an 11 inch drum. Stamped on the drum is "Max Dia. 11.060". I think the drums on the front are 11 inch also. I measured the inside width of the drum where the shoe makes contact and it is 2 inches. The width of the shoes measure about 1 3/4 inch. Any ideas on what parts, including new drums, I need to order? I thought Mustangs came with 10 inch brakes. I assume the PO did a conversion.

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