If the overall lengths are different then drive shaft will need to be changed.
Not sure where you are reading that specific info but many tech articles were written many years ago and would only apply to transmissions up to that date.
And even then they can be incorrect, while the tech articles are usually better than the Ford service manuals they can have errors.
Usually what happens is someone sees the error and reports it here:
http://www.therangerstation.com/forums/forumdisplay.php?f=5
But it needs to be a specific "this article" has "this error"
Then the administration corrects the error(s) so the article is up to date.
While I still believe EVERYTHING on the internet is TRUE I do have to accept the fact that some can misinterpret the TRUTH as a error