v6 to v8

I have a 2002 mustang 3.8 and i just broke well during the three weeks or so ive been with out a car i have decided that 10 years 147k miles maybe time for an engine rebuild seeing as how the previous owner ran the shit out of it but its still tight to take off and agile so im thinking im just going to get the problem fixed so it runs so i have a car but i will rebuild. now if i rebuild im thinking why not go the whole nine yards im planning on going to pull a part and getting the modular v8 and tr3650 that come with the gt and just working on the engine and then when im done itll be time to rest the v6 that is in and and ill have a new rebuilt v8 ready to give my car "Abella" the power she really deserves. so my question is if i am going to upgrade what all do i need besides the engine and tranny.

I'd say it is cheaper and easier in the long run to drop a junkyard V6 back into it so you can sell it and buy a V8 Mustang.

yeah no i finally just said screw it im going to get another v6 and rebuit it so i can still drive it and just make this my fuel efficient car and them my friends selling me his old 67 stang manual for 500 and ill make that one my racer but even still if i replace my v6 with another v6 of the same type what do i need to change like getting the ecm and ford engine imobilizer to match up