The main issue with newer options for rear axle conversions is the overall width.
There is a great write up related to the conversion to the 14 olt GM axle that I bleieve includes information about the various options and what the trade offs are for the different axles. I bleieve it is a Tech Tip but I need to find it and will update this post with that information when I do.
It is apparently not a Tech Tip and only discusses the 14-bolt but the dimensional information is useful evaluating other axle options:
https://www.stovebolt.com/ubbthreads/ubbthreads.php/topics/1249600/14-bolt-axle-swap-info.html
