are 2nd Generation TIIs trannys different or the same in between years. i.e. are the 87-88 TII tranny's different than 89-90 TII trannys? thanks.

 

As for "Bolt-in" and "Plug and Play", they are identical between S4 (86-88) and S5 (89-91) models. You must however use the right differential crossover for the right tranny. (IE: An S4 transmission mount won't work on an S5 transmission and vice-versa)

The only difference internally that I am aware of is that the S5 transmissions have a reverse gear syncro. The S4 tranny does not.