from injectors to carb.

My stang has been having a problem for about a year and it is rusting in my garage. It has a rough idle and it hesitates after driving it for about 30min. When I disconnect the IAC it idles better but I still get the hesitation. Whats weird is that when I disconnect the elbow from the throttle body it makes no difference, shouldn't it mess up the idle completely?? view my previous threads if any of you want the history on it. My real question is, what exactly do i need to swap from fuel injection to carburetor?? I believe this would solve my problem.