1967 F100 rear brake drum issue

[Bob67f100]

My father and I are having trouble locating the correct rear brake drum. Ordered drums for a 67 from LMC, and the drum sits flush with the axle but leaves about an inch and a half gap to the backing plate. And this is for 11" x 1.75" shoes.
Ordered drum for a 1968 thinking maybe axle shafts were changed sometime. These drums fit fine until the lug nuts were tightened, then the drum was locked up. The inner lip of the drum was hitting the backing plates.
The original drums were beyond use, but we still have one thankfully for measurements. Hopefully someone can point us in the right direction.
The numbers we could see on the old drum are;
KH A17(best guess, really rusty) 6 50851

Drum dimensions

2.84" axle hole
1.88" inner brake surface
2.817" mating surface of axle flange to outer edge of drum
12.75" overall width
11" inside width
2.95 total height

Axle tag has WDM -H 3.25 7AA 313 so should be correct 67 axle.

Thanks in advance for any help.

[JWW]

Try Rock Auto: https://www.rockauto.com/en/catalog/for ... ,drum,1744