hey guys, wondering if anyone can help me out. right now i own a 2000 celica gt, what i would like to do is change it to a gt-s engine, 2zz. Now my question, is the only difference between the 1zz and the 2zz engine are the heads? or is it the Whole Block? and if it is just the head, do you guys think i would need the 6sp tranny to go with it? or can i just keep the gt tranny. thanks for your time.