340 Duster

Just getting into MOPAR! My friend bought a 340 Duster and we started to go through the car. Got to make sure it is worthy!! Found the rear end had spacers under the drums.?????? removed the spacers, put the tires back on and the rear end is locked up. Ordered new drums and they are the same (8 3/4 rear end 10" brakes). Figured i would ask the experts. Please advise. Cool car, just needs to be right.