10" rear backing plates??

with what you seem to have it sounds like 1.75 shoes are what should fit.

Recap...
Your drums, backing plates, axles, etc. all fit together as an assembly, correct?
Sure is nice of you to take time to help! I have some Chevy friends... They are having a good Laugh.
Yup,,, everything seems to bolt up nicely,,,, till I put shoes on?
I will get out to garage takes some pic;s and get back.
Nothing grinding, no gaps btwn drum and backing plate...

Let's see a better picture of the pieces.