I would go with the custom 74 headers from RPW or something if I were you. For $750 I believe that would be a better buy. You won't have to worry about fitment issues. The obx headers will have other problems as well when you goo to install them. You will need to modify the rear motor mount and some other stuff that I can't think of. On
FL3S there is a good thread about what needs to be done.