8 3/4 backing plates

Does anyone know if this swap will work? We bought an 8 3/4 rear end without brake backing plates. We have a 76 8 1/4 rear with 10 inch brakes on it. We removed the backing plates from the 8 1/4 and they fit on the 8 3/4, we bolted in the axles(everything still seems to clear) and installed the drums. The drums slide up against the axle flange, cover the backing plate and rotate without rubbing. Has anyone performed this swap before? It sure would save some money that could be used else where for our Swinger project. Any advise would be helpfull. Thanks