7 1/4 To 8 3/4 drum brakes

Are the 7 1/4 and 8 3/4 SBP drums, backing plates, shoes, the same? I am stripping down a 72 6 cyl Demon with a 7 1/4, and will be installing an 8 3/4 SBP in its place. Before I pitch the whole 7 1/4 setup, should I save the backing plates etc to help assemble the new 8 3/4. I have an 8 3/4 empty housing but don't have the axle end/brake hardware yet.