Crossmember notch or Crossember drop?

[milehightoyz]

Sorry if this has been asked before but I could not find a thread on it. Ive seen a few threads on 1.5" xmember drops and Ive notice some people such as captkaos will section and drop the entire top of the crossmember down an 1.5":



And some such as fastbagged68, and phantom dually, have only notched the area where the framerails will sit recessed.



is there any preference as to which is a better way to go? what are the differences? the only difference I can see offhand is motor placement but that can be addressed fairly simply with diff motor mounts. I know that fastbagged and phantom both are going with custom built LCA's is this coincidental or necessary when doing it that way? Any info would be greatly appreciated.