All of the JBA headers I've installed didn't fit very well. They normally hit the pass. side frame. The ones from Ford Motorsports fit like a glove, I haven't had any problems with those. Watch out for the cold air kits, most of the 05 and up stangs run lean once those are installed with a good exhaust. As long as you get it tuned afterwards you'll be fine. With an automatic I'ld recommend getting it tuned anyway it'll be alot more fun to drive. JMHO