Can you take a photo of the hub?
Have you made sure the parking brake is not engaged?
Were you able to adjust the brake shoes away from the hub ID ? See attached document , Adjustment - Rear 1, 1/1/2 and 2 Ton
You did removed the two retaining screws that retain the hub to the spindle?
Does the hub turn freely , can you spin the wheel?
Link to Old Car Manual Project -
http://chevy.oldcarmanualproject.com/shop/1947truck/index.htm