03KBCobra24

hey everyone, this is my first post... mainly i have just one question..i have never done a engine swap in a ford... my g/f has a 00 steeda mustang 3.8, and basically she wants something with more power.. and my friend scott sold us a 5.0 with a cam, 1.6 rocker-arm, and a set of shorty headers for 350. well her brother said to her tonight she would have to do a tranny swap.. well the guy i got it from is a very respectable mechanic and i worked with him... would i have to get another tranny... or does the stock one bolt right up to it... like he said... i just wanted to ask you guys.. i read alot of your guys post and i believe you guys are very smart in this engines compared to me... thanks everyone that post.