Uh, actually the SBP ones that he's looking for are A-body specific, nothing else had the 5x4" pattern and the SBP axles have a different flange offset. No mixing and matching SBP and BBP backing plates.
And I believe they are also 8 3/4 specific, I don't think the SBP 7.25" backing plates interchange. I may be wrong about that one though, that's just what I've heard.
