8 3/4 Rear End Brake Shoe Help

My brother purchased a used 8 3/4 diff. of of a 1969 Formula S Barracuda. I'm in the process of rebuilding the rear. The brake drums and baking plates were removed along with all the brake components.
The old drums measure 10" x 2 1/4" on the inside so that's what I ordered for replacements from RockAuto. Now I'm looking to purchase new brake shoes and I'm not finding rear shoes that are this size. RockAuto lists rear shoes that are 10" x 1 3/4". The only shoes listed that are 10" x 2 1/4" are for front drums.
Can front brake shoes be used in the rear or are there design differences? Should I just order 1 3/4" shoes instead?
This differential will be used as an upgrade from a 7 1/4 unit in his 273 notch. Thanks for any assistance you can give me.