Starting to look at doing my 89 740 front suspension. Looking at my green book service manual it tells me that my year ( USAand Canadian) has the aluminum lower control arm. I have not found an aluminum replacement but plenty steel ones ranging from $35 to $150. I can also just buy the bushings but just considering the easy way. It seems the control arms are a direct replacement but with the steel ones it looks like you need to replace the sway bar ends too as they are different. Just asking if anyone has done this replacement with steel and did you run across any other differences. By the way at 375K my bushings are rock hard

 

Just a thought. If the subframe bushing is good then skip it and replace the strut rod bushings (and others). I guess it depends how deep you want to get into the project.