Well. Lets see. Given the choices for 86, 2.5L, 2.8L V6 or the 2.1L Renault, only two of those engines share the same 90* GM bolt pattern. Your choices are limited to the year 86. I could be wrong on that and I'm sure someone will correct me but you have a Torqueflite A904 auto trans, AX4 and an AX5. If you get lucky and can find a trans that will bolt up behind either the 2.5L and 2.8L that's better than the AX5, you're in luck. If you find an AX15 behind a 2.5L Dakota, well that's the best trans you can put behind either. But if its the Renault, yeah you only get the AX5.