Having done my first swap to efi which in my opinon was very easy using the FAST EZ-EFI system and thatwas over 10 yrs ago. that system i beleive has been updated and there are other systems similair to it. my current ford computer system is based on the 5.0 harness and computer but its on a 351.
given the choice to do again, id stick with the easier FAST EZ EFI. the motors will make the same power i believe using the carb versions of intakes so long as they go with the correct heads and cam combo, etc. and the fast ez efi essentially just replaces the carb but bolts right on.
the fast system is very plug and play and self learns, the ford system you will need some one who knows wiring to wire it up and to tune for you.
the fast system or similair keeps the original look while the new ford systems look newer of course. also the newer system will require a MAF, cold air intake, Throttle body, all of which should also match your intake for best results.
one thing in my which youll need regardless is return line to the tank. you can either run a braided line, or a hard line. then you can adapt you tank by adding a port.however i know there are new tanks out there which have the fuel pump, inlet and outlet already integrated. also those new tanks are baffled inside so you never lose pressure. im thinking to upgrade to one like that.
next,for your AOD, if possible try and get a AODE. the regular AOD lock up version is only good for like 260 -300 hp i believe. in that stock form it will break. I broke mine by simply downshifting. I then went with a non lock up setup and i even went with a Lentech valvebody to hold higher line pressure so i can drive it like a stick. Now if you go with an AODE, you can still keep the lock up version but it wont lock up until preset rpms and what not. they sell a controller for them as well to be able to use them on non computer controlled or motors that dont have a setting for that. as my AOD sits, it can take up to about 600HP. (im working up to that number)