4 1/2" Brake Drum & Band. 4.5" OD Machined Drum for Brake Band Use. Drum Specs (3) 5/16" bolt holes on a 3-3/4" bolt circle. (4) 1/4" bolt holes on a 3-3/4" bolt circle. (4) 9/32" bolt holes on 3.225" Bolt Circle.
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