Engine swap

I have a 2012 v6 mustang that ive modded and all ive needed is a v8 engine and recently got ahold of a gt 3v engine just wanted to know if there would be any problems with swapping the motors or if any modifications are needed for the swap. Any help is appreciated
 
Why do you want to swap a 3V into that car when it the V6 makes about the same power as the 3V did?

At any rate you would most likely need a full harness and ECM, and probably also make sure the fuel system is compatible among other things. TBH I don't know what the particulars would be but it would be pretty involved. Maybe someone else can chime in.