Then the 87 isn't a 3-speed. It's a 4-speed AW-4. They are both AW-4s. And I do believe they are swappable, but I'm not much of an auto expert so wait until someone can give you confirmation on that. After the swap, be prepared to try and track down why overdrive wasn't working in the 87. I think overdrive is computer controlled so there may be a fuse blown or maybe the trans computer is fried. Or it might be a problem with the trans itself Once again, I'm out of my little bubble of knowledge so I'm not sure what you should check first.