Ok, not sure if this helps. I went from a C-4 ('73 behind a 2000) to a T-5 behind a 2.3. I also swapped out the 6-3/4" to an 8". The original driveshaft fit perfectly.
So, assuming the transmission location remained the same in your car, - if the C-4 and the T-5 (from an '88 Turbo Coupe) are the same length (I don't know that they are) then I would say probably yes.