4.2 to 5.4 swap??

[GnFnRs]

i know there are tons of very good ford techs here so i have a few questions.
i just got a very clean 1998 f150 ex cab. it has a guncked up and dead 4.2. i want to change to a v8.either 4.6 or preferably a 5.4. but i want to know what has to be changed and what can be salvaged?...i know the injector harness only has 6 plugs and i'll need 8 obviously.but can i just change the motor harness that plugs in on firewall or do i have to change the whole thing from the ecm to the motor? also will the trans from the v6 work? how about the fuel pump? motor mounts? if it's too much trouble i'll thro a carb'd 466 in it..lol. thanks in advance for any and all info..

[Errick NDA]

I would think you would be better off changing the hole harness! Just look around for truck that has the motor you want in it and swap every thing ,a wrecked or junker that is !

[Peppy]

a 4.6 is an easier swap the ecm to bulkhead harness is the same and the the drivetrain requires less modifications althought you need the 4.6 tranny y- pipe etc