Noooo....'87-93 5.0 TB's DO NOT fit. They had the IAC on top of the throttle body, with the linkage facing the firewall, so in order for them to work on the 2.3L you'd have to flip them over which would put the IAC facing the valve cover and there isn't enough room there. THe only ones that fit are '94-95 Mustang GT throttle bodies, or Super Coupe throttle bodies. And trust me, even they take a good bit of work. (you have to drill new holes in the throttle body, port out the intake to the size of the new TB, and make modifications for the TPS.
Also I doubt the gains on a n/a 2.3L would be worth the work.