SBP 8 3/4 backing plates, drums, guts

I was following your thread about this and there seemed to be some disagreement about the backing plates, read through it, but never fully understood why it would or wouldn't work. I know the drums won't work, but what's the deal now on the BBP backing plates?
and thanks for the reply
Correction: It was the drums not the backing plates, so, looks like I'm a lot closer, not sure about paying the ebay drums at about 200 shipped.
anyway, thanks for the response.