early B body rear in my duster

If it is indeed a 65 or later axle, the drums should slide right off. If there is a large nut on the end of the axle shaft on the outside of the brake drum, you have a pre-65 axle and should seriously consider getting one of the later ones. These have keyed hubs and are known to fail in performance applications, as well as being obselete and harder to work on and find parts for. The "pumpkin" is the same, save it if you go to a newer axle. Check the casting # on the pumpkin, if it ends in 657 or 741 it is also weaker and very hard to find parts for, you want one that ends in 489 or 742.