I have an '88 cougar xr7 and I just switched out the 5.0 with one from a low mileage '87 20th anniversary that was wrecked. I was going to use the transmission from that as well until.......I saw it was smaller!!! one has a "56" stamped on top and the other had a "57" stamped on it. the '87 was also smaller in appearance. yet everywhere I look, all the info sites continue to say the cougars had the same 4spd AOD tranny in all models....... can somebody enlighten me?