I can't find any online! Swap over to 10 x 2 1/2.

"Note: A-body 8-3/4″ axles were equipped with 10×1-3/4″ drum brakes. Replace these with 10×2-1/2″ or 11-2-1/2″ brakes and associated hardware from the donor vehicle or similar."

http://www.dutchmusclecars.com/site/?p=184