12 bolt rear issues

[609thomasm]

In the pics attached are two 12 bolt rears out of 67/72 trucks. (both coil spring). Notice the difference in the distance from the axle flange to the wheel cylinder. One is about a 1/2 inch greater. My issue is that when installing the brake drum on the one with the greater distance the brake shoe does not get completely covered by the drum. The shoe surface of the drum doesn't make it all the way back. Drums and shoes are 11" X 2". You can see in the pics that the extra distance is due to where the flange is attached to the axle tube, one welded on further from end of tube than the other. Trying to figure this out so I can use the rear with the greater distance but need to know if there were different drum or other options for the brakes. The backing plates and axles from both seem to be the same. Thanks for any input.