Vewdew- I have a selectable 2wd/3wd/4lock King Quad front diff in my 03 500i now. It is a direct bolt in, but you have to do some fabrication to the upper left A-arm because the KQ diff is a little wider. The front drive shaft also has to be extended and custom front Cv axles have to be built because they are different.

 

I agree VooDoo, The other sad thing is In 98 the 250 and 300 A/Cs had the option also.

ODB, After your post I looked at the parts break down of the 03 vs 98 and there are allot of differences on the front end. Different diff, Different A arms, Different drive shaft and the CV axles are different. I wonder if we would end up doing all the changes that you referred too with our OLD units.

I live a very sheltered area hear so all I can really do is look at pics to see the new A/Cs The closest dealer (that I will step foot in) is almost 200 miles away. That's were I had to go to get my 250. So I am just asking questions and trying to figure things out.