If i'm not mistaken, the 89's had 2 versions of the KM132 5-spd tranny (one for the 2.0 and one for the 2.6), the KM145 (5spd 4x4) and for automatics they have a AW327 (2wd) and the KM148 (4x4) although I'm not sure what the bellhousing size difference is from the 5 spd's to the auto's. I did the swap from a 2.6 to the 2.4L in my '89. The wiring had it's challenges (the steering column harness is not plug and play, easy fix if you can get the controls with the new harness, but I had to swap the guts into my existing box for turn signals, lights, wipers ect.) and depending on what differences there are between your truck and the donor. I had to get a little creative on mine to turn the 2wd harness from the 2.4 into a 4wd harness in my truck, nothing real tricky just a bit of a pain in the behind. I'm not sure what other guys have done for swaps on their trucks being able to keep the stock tranny but with the 2.4 at least you are still working with the same color codes for more of the rest of the electrical within the truck. It's a lot of tedious work but my 2.4 is a pretty strong and smooth little motor. There's a lot of guys on here with a lot of knowledge, just trying to let you know what I do