Back in the late 70's, there were shops that installed T tops. But, that was
in the days when everyone wanted T tops and there were lots of F bodies around,
besides other GM bodies that took them as well.
If you want to have them, look for one that has them from the factory to start
with. One word of warning, they leaked from the factory, so look for rotted
floors and windshield pillers.
If you want to learn more about the roofs look at
These guys go into great details on T tops.
One other note. On the 4th generation F-bodies, T tops can be added. The last
generation were designed for T tops. The second generation were not.