I'm pretty sure the 1/2 ton drums will interchange front to rear, BUT- - - - -the fronts were riveted to the hubs and unless somebody has cut the rivets away, you'll probably find front drums with the hubs still attached. A little work with a drill press to take the heads off the rivets will free up the drums so they can be slipped over the rear axle flange studs. In some cases the drums were a slip fit, not riveted, and they were held on with sheet metal spring steel retainers to keep them from coming off during a tire change. I've seen some front hubs that had the lug studs swaged into place, and they also held the drums onto the hub by the swaging procedure. A special cutter was required to spot face the swage away before removing the drum, in that situation.
Jerry.

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
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