64 Panel rearend question

[scubasteve16]

I was working on my Panel today and noticed that the brake drums were not all the way up against the backing plates so I did some checking. They are all they way against the axels just not backing plates. I called the prior owner. He said he put 70 axles in the factory 64 rear end so he would have 5 bolt axles instead of the factory 6 lug. From reading here I know this is not going to work. Now my question is if I put a complete rearend from a 68-72 Chevy truck will everything line up or will I have to change where the arms mount up? I am hoping it will all line up as I am not no expert welder and dont trust my welding skills enough to weld on the rearend.