the 5.4 will swap as long as it is SOHC, the DOHC is too wide and will require more fabriction than it's worth
i didn't mention anything about the 4.6 DOHC.
i'll repeat, the 5.4 will swap AS LONG AS IT IS SOHC, the DOHC is too wide and will require more fabriction than it's worth.
the 5.4 is available as a SOHC AND a DOHC.
i'm a member on tccoa. and yes a 5.4 SOHC will swap and has been done on a few occasions. off the top of my head J.Miller is a guy who has done the swap so try again.
EDIT - Oh look, a tech article from TCCoA. So
I thought I read about the DOHC 5.4 not fitting the shock towers on an MN12.It was hitting.I read on TCCoA some time ago and it was an Aviator motor I believe.But yea the 5.4 is only a torque benfiet and hardly worth it IMHO unless you're going with some kind of forced induction.