I live on an island where the top speed is 25MPH. Steep winding roads that are mainly unpaved. I saved the 83 sedan out of the junk yard and have been harvesting engine and other misc parts over the last few years. It needs a new engine which I have. I need lower gears for the hills. I was thinking of swapping the diff for a 240D diff(3.69?) to achieve that. By swapping the diff for lower gears, how does that effect the shifting/vacuum components of the automatic trans? Realistically it would probably only need one shift to get to 25MPH maybe two. Also, I know that the auto trans starts in second gear even when the "L" position is selected. Are there anyways to make the trans start in first?