90' engine in 87' w/ tranny issues.
 

I took my 1990 7MGTE and put it a an 1987 (replacing a 7MGTE that threw a rod), and used the 87' wiring harness, because all the engine side component plugs matched, not so on the chassis/computer side.

It runs great and smooth, but a little sluggish, especially off the line. I am wondering if there is a major difference in the transmissions or torque converters between 1987 and 1990? I do know the Tranny computer interface is different which is why I did not also put the 90' tranny in with the motor.

If there is a difference, can it be addressed with the proper torque converter or do I need to work installing the 1990 tranny and computer.

Are you using the 90 ECU with the 87 wiring harness?

No, all 1987 computer and wiring. The only 1990 components are items on the engine itself (injectors, sensors, etc). It was because the ECU and other chassis-side connections did not match up, that I connected using the 1987 wiring.