[Breeang]

I have replaced my strut insertsand have two questions:
1 I have used Bilstein inserts and I think I read somewhere some while ago that you do not need the rubber bump stop tube on the top of the insert as Bilsteins already have a stop built inside . Is that correct?
2 In the Porsche factory parts catalog, around the top of the strut shaft, immediately above the dust cover there is shown a strut spacer (item #6). This item appears to have been left off the part number list on the opposite page and no one seems to stock it (discontinued). I never had any on my supension before I started so is this spacer necessary? If it is, does anyone have any dimensions so I can find a substitute?
I thank you .