if you are happy with 7.3 power and all just not the issues build one
if you want more power more cost and more bolt on mods go with a cummins
but you need motor mounts made up
mod the fan shroud
hammer the firewall
and some wiring but wiring is simple with a 6bt
then yo got the tranny you have a few options
stock ford unit with an adaptor (costly)
dodge unit moving the crossmember and if its auto youll want a manual swap dodge autos suck new drive shafts
then if you you use the dodge tranny you
use dodge t case or a divorced unit like a np205