So Sadly I totaled out my 02 Caviler. I found a 2000 for $800 but its only a 3 speed. So I have a spare 4 speed sitting in my garage, and I'd like to change the 3 speed to a 4 speed to improve fuel economy and reduce stress on the engine when driving down the turn pike. I also found a 99 that needs an engine and trans for $100 along with a few other parts, so the parts from the wrecked car are spoken for. So the question is what components have to be changed to drop the 4 speed in? is it just a matter of changing the engine harness the cooler lines, transmission control and program the PCM to understand it has the 4 speed? I can swap the trans at work and program it no problem. I can pull pretty much any info on the 4 speed, but the three speed is a bit difficult.