Technical Rear drum brakes

I have a 9 inch rearend I can,t find what the drums fit. On the drum it has these numbers KH 1238 13 41669 overall depth is 3.146 od is 12 11/16 11 inch brakes center register hole is 2.430 This has been a challenge trying to find these drums. Any help will greatly appreciated.

 

Understand the depth and register, but have no clue on the 12 11/16 11 od?

 

So the drums are 11" diameter, right? How wide are they? What's the lugnut bolt pattern?

 

4 1/2 3.146 deep 12 11/16 over all od

 

the overall with of the drums the outside diameter

 

Brake drums are generally listed by the inside diameter and the width of the actual surface where the brake shoe rides in the spec sheets, not the overall dimensions. So post those measurements and some pictures of the current backing plates. It can really help when trying to figure out the years they were used. Any numbers on the wheel cylinders can also help in identifying what you have.

 

Usually the drum is about 1/2" deeper than the brake shoe width. A 2" wide lining should have approx. a 2.5" nominal drum surface depth.

 

Piggybacking on 1trickpony's explanation;
It's easiest to measure the shoes, which are usually either 10" or 11" diameter and either 1.75", 2.0", 2.25, or 2.5" wide.

Most small to medium size cars used 10" rear brakes, in 1.75", 2" or 2.5" widths. The larger cars and many trucks used 11" brakes, typically 2.25" wide.

Knowing the lugnut bolt pattern can help differentiate between a car rearend (5x4.5" circle) and a truck rearend (5x5.5" circle).

Here's some more good info:
http://kevinstang.com/Ninecase.htm