Here is a picture of an A body 8 3/4” backing plate. The flange offset is 1 7/16” or 1 3/8”, I would check the offset of your current backing plates to confirm that you have the correct backing plates. Did you get the complete set of 1.75” drums and backing plates together, or are these pieces that were put together separate? Most people don’t know anything about the small bolt pattern stuff, which is all I run on my A body cars. I have a few extra sets of everything if you find out you need any or all of the components to make up a complete set. Including the original style bell flanged drums.
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