Ur tranni wont work, u need one from a v8. You dont really have to get a new pump, u can just get a fuel pressure regulator, either way works though.
Also i believe you will want to beef up the front suspension for the heavier engine.
Lowering springs, maybe, i think they should be thicker though. I really dont know much about suspension. I remember reading an article about swapping a v6 for a v8 in a 65 mustang so im not sure if that applies to u.
What about the K member? If its a 96 then wasnt the k member modified to allow for the 4.6? Or will the stock K member work with the Motor mounts? Cause i remember seeing somewhere that the V6 mounts are the same as a 302 or 351.