Just thought people should know. These are the fog lamps I have on my car, and they fit nicely in the non-T/C air dam.
http://www.andysautosport.com/ford/1989_1992_thunderbird/lights/fog_lights/pilot_motorsports/pilo00025020.html
(http://i28.tinypic.com/zx6vq8.png)
The downside is that they don't seem to shed much light, but I'm going to try moving mine forward and/or convert to HID to see what happens. Since these have been hard for me to find I'm picking up another pair in case something happens to my lenses. Anyhow, for a decent sort-of-stock look these work pretty well.
I had some similar ones in both my '87 Sport and my '88 base (until I put the TC header/bumper on). They're easily found at Princess Auto if you live in Canada, and they're also quite cheap (under $30). I think the ones I used were the "Blazer" brand name.