bilstien suspension 1989 635csi highline

Can anyone help me please i have recently bought a pair of rear Bilstein shocks and springs on Ebay for £50 deliverd for my 1989 635 Highline they are in very good condition and have the extended lower bush to fit my car, but i am having trouble identififing them they are yellow in colour with 3 adjustment groves 10mm apart and the part number on the bottom of the leg is 9290727H01 and also the springs look diferent to mine these are black spray painted with 2 yellow brush painted marks on the top coil my rear springs are the same diameter all the way down but these are about 1mm thicker until you get to the lower 4 coils then they start to reduce in diameter each one alittle thinner than the last there also seems to be evidence that the bottom 4 coils have been touching but only the bottom 4 coils, i can not see any part numbers or manufactures marks on them as you would expect to find on a after markrt spring ,i have fitted them and the car now sits 17mm lower at the back with the sping perch in the middle grove and feels a lot firmer. I also have a pair of front shocks from America which i believe are  heavy duty bilsteins these are also yellow in colour and have a very thick chrome insert in the shock and a blue protective gator the part number is p-36-233-h002 i have been told that these have almost the same damping value as the sport shock  but are the standard lengh could i fit M635 front springs with these shocks as i have also been told that these springs are only about half an inch lower than standard springs but firmer  I hope someone is able to help me please.                                                                                      

Those front shocks are the B6 Sports (part number 34-002339) which are the same part number as the standard E28 M535i units. They will be fine with the existing springs or the M635CSi ones - or a short (25/30mm) drop using H&R springs. These shocks will really sharpen up the handling and ride. It would be worth fitting new top mounts though - the B6's are quite a lot stiffer on bump and reboiund than the standard Boge shocks and will quickly finish off old top mounts.

Euro Car Parts or Andrew Page will be able to supply some proper quality Febi (Bilstein) or Lemforder items for not much money. It makes sense to change them whilst the strut is apart.