8 3/4 Backing Plates

[Mopar Crazy]

I recently picked up a 70 Duster. The 8 3/4 has a small bolt pattern. I want to change the axles to the large bolt pattern.
I was told I have to change the Backing Plates too,  is this true???
Thanks
Pete

[John_Kunkel]

Yes, the backspacing of the backing plates must match the axle flange extension and drum width.

Easiest way to go is to get the entire brake setup (plates, drums, shoes, hardware) from a big bolt pattern car.