I've done so. Up front, I'm running the Mopar Action junkyard 11.75" disc brake swap. Right now I have a late A-body 7 1/4" axle with the large bolt pattern for the back. I've got an A-body 8 3/4" axle that's been modified for 11" drums ready to swap in, with new Moser LBP axles.
Do later components like volares/ later a bodies swap in?
F-body (Aspen / Volare) stuff does not directly swap over, though you could probably get their axle in by welding on non-Isoclamp spring perches. The F-body front disc spindles will bolt in if you use '73-'76 A-body upper control arms and ball joints. F-body control arms don't fit though. Same goes for M-bodies (Diplomats, etc), which are a continuation of the same platform. Any later A-body suspension will bolt in.
Is there a beefier rear out there that drops right in with out having to have it narrowed?
Besides A-body rear axles, Ford 9" rear ends from a Mustang (or Maverick or Granada) are the right width. I think you need a U-joint conversion. But there are all in the Mopar family options.