I'm going from recollection of last year and can verify this weekend but I swapped my 1 3/4" for 2" on a '69 9" but my 8" looked the same.
I did not have to change backing plates, I bought 10X2" shoes, raybestos drums for 10X2". The only other item that was different and prompted a trip to the parts store was the brake spring hold down pin that goes through the shoe. The 1 1/2" shoe pins were too short and the store had 2 other lenghts. I bought both and returned the box that didn't fit (I think they were for 11X2 1/2" shoes so they were too long TMR).
Using the 1/2" wider shoes and drums did not push my tires out any farther but I didn't bother to see what was different about the drums that allowed this. I think the 1 1/2" drums had 2" wide pad surface and the thinner shoes just didn't touch the entire width.
Jon