I've changed out the T5 on my TurboCoupe once already, and will be doing so again in the near future. When I changed it the first time, I also changed out the flywheel, clutch, and pressure plate. The orignal transmission would not go into first unless at a complete stop. I replaced it with a T5 from a 1987 TC, which is now going out.
The clutch and pressure plate listed in parts manuals for a 1986 TurboCoupe is smaller than the one listed for the 1987/1988 TurboCoupe. I compared the mounting of various flywheels and such at the auto parts store, and found that even though the clutch sizes vary, they will all pretty much interchange. So, I opted for the 1987/88 setup (slightly over nine inches) instead of the 1986 setup (slightly under nine inches.)
Below are some pictures of the T5 without the bell housing, which I hope are helpful to someone.
Side view of a T5 from a 1987 TurboCoupe.
Rear view of a T5 from a 1987 TurboCoupe.
Top view of a T5 from a 1987 TurboCoupe.